ArcGIS Online

This tutorial by Tierney Steelberg, Digital Liberal Arts Specialist at Grinnell College’s DLAC, is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

This tutorial was reviewed and edited in spring 2025 by Kailee Shermak ’25, a student and Vivero Fellow at Grinnell College.

Click any link to head to that section.

What is ArcGIS Online?

ArcGIS Online is a cloud-based online mapping software that allows you to create complex digital maps for data analysis, as well as easily share them with others. ArcGIS Online replicates in a browser-based version many of the functions of the ArcGIS Pro desktop software application, though it is not quite as powerful.

ArcGIS Pro is available on campus computers in DASIL and some HSSC classrooms. The desktop application allows for more statistical analysis and visualization options, but ArcGIS Online has a more gentle learning curve for beginners. Both ArcGIS Online and ArcGIS Pro allow you to create web maps.

In this tutorial, you will learn how to use ArcGIS Online by mapping historical data from the Iowa Townships Project.

Logging In

Everyone at Grinnell has access to ArcGIS Online through the College: your account on the platform is created the first time that you log in. You can access your account by clicking the blue “Grinnell College” button and logging in with your Grinnell College credentials at https://grinnell.maps.arcgis.com/home/index.html. It is used in the browser, so you do not need to download anything special onto your computer.

Working with Data

ArcGIS Online requires spatial data for mapping: any data that you upload to ArcGIS must have some type of spatial identifier.

Latitude and longitude coordinates
Street addresses
States/counties/countries
Zip codes

Spatial data can take many forms, including:

CSV (what you’ll be using for this walkthrough): commas separated value – basically a spreadsheet that is interoperable across platforms
GeoJSON: geographic text file
KML: geographic extensible markup language file
Shapefile: a file format for storing geographical location and attribute information data, and they are actually made up of a grouping of individual files, compressed into a single .zip file that is uploaded all at once to ArcGIS Online
- You can play around with some spatial data in shapefile format in the optional Going Further section of this tutorial.

Downloading Data for this Exercise

Click this link to download a dataset for this tutorial. You’ll upload this data into ArcGIS Online in order to map and analyze it. This dataset is a CSV file that contains Town of Grinnell census data from 1900, cleaned and formatted for use. You can look at the Iowa Townships Data Codebook to learn more about what the different abbreviations in the dataset mean.

Let’s reflect! Download the dataset CSV, look through it, and think about what you see…

What do you notice about this data?
What questions do you think this dataset might help to answer, if visualized on a map?
Are there particular variables you’d like to map?

Web Maps

What’s a web map? Esri, the company behind ArcGIS and ArcGIS Online, describes a web map as “an interactive display of geographic information that you can use to tell stories and answer questions” (source: Web maps).

Creating a New Map

Access your account by clicking the blue “Grinnell College” button and logging in with your Grinnell College credentials at https://grinnell.maps.arcgis.com/home/index.html. After logging in, you will be directed to the home page of ArcGIS. The top of the screen has a menu which gives you several options:

Gallery: view other maps made at Grinnell College
Map: create a new map
Content: view the maps that you’ve made – so when you leave the map we’ll be making in this exercise, you’ll be able to return to it via this tab

Click Map in the top level menu of your ArcGIS Online homepage to create a new map. From there, you will be taken to a new blank map for you to make your own!

Classic vs. New Map Viewer

Esri is in the process of releasing a new Map Viewer. For the purposes of this tutorial, you are using the newer Map Viewer. Make sure you are using the newer Map Viewer by clicking Open in Map Viewer in the top right hand corner of the map page. (If it says Open in Map Viewer Classic there, you’re already using the newer map viewer and are all set!)

If you would like to learn more about the new viewer and some of its new features, you can read this article from Esri, “New Map Viewer in General Availability.” Map Viewer Classic is deprecated and will be retired in early 2026.

Customizing a Map’s Appearance

You can customize the way your map looks by clicking the Basemap button (shaped like a collection of basemaps) in the left-hand menu of the map view, and then selecting your chosen basemap. You can change this at any time, so can come back and make edits for the best base map for your purposes once your data has been added to the map.

Let’s reflect: how might different basemaps influence a viewer’s experience of a digital map?

Saving Your Map

Click the Save button (shaped like folder) in the left-hand menu of the map view, then click Save As to save a new map or a new copy of an existing map: you will be prompted to give your new map a title and tags (required, but you can choose any you would like), and to add a summary, if desired. If you are working with a pre-existing map, just click Save to keep saving it to the same place – make sure to do this regularly while you are working so your changes are saved.

Layers

What’s a layer? A layer is a collection of specific geographic data added to your map. Maps can have multiple layers that can be shown concurrently or hidden as needed to allow you to interrogate the interactions of multiple datasets or to focus where you need to.

Adding Layers

There are a couple different ways to add layers – for the purposes of this tutorial, you will be adding layers of data by file. This data takes the form of a CSV. This CSV will show up on your map layers in the form of points. As previously mentioned, for this tutorial run-through you’ll work with the Grinnell_1900_Geocoding_Result_Tidied.csv, which is points data relating to the Town of Grinnell. (When using shapefiles, you want to make sure to keep the shapefile compressed in .zip format – some browsers try to open compressed files for you automatically, which is not helpful in this case.)

Click the +Add button (shaped like a plus sign) at the top of the left-hand menu.
Select Add Layer from File.
Upload the CSV file (or the entire .zip file, in the case of a shapefile).
Click the Import Layer button.
For the purposes of this tutorial, select the Upload this file as an item and add it to the map option (as there is no need at this time to create it as a hosted feature layer – more on those below).
Optionally, you can update the display names for fields (how they will show up in the legend and in the data table for the map) and update the field types (can potentially useful if there is a field of numbers you wanted treated as text, for example – like treating a zipcode as text rather than a number where there are greater/less than relationships). Then click Next.
Make sure the fields with geographic coordinates are matched correctly: longitude is X and latitude is Y. Then click Next.
This process adds your CSV as a file to your ArcGIS Online account content. Give your item a title, put it in a folder if desired, and optionally add tags and a summary for your CSV as needed for your own organizational purposes, then click the Create and add to map button.

Congratulations! You’ve added a new layer to your map.

You can use the eye icon that appears when you hover a layer’s name to show/hide layers as needed.

Duplicating Layers

You can make copies of your layers, so you can use the separate copies to analyze different aspects of the data. Simply click the options button to the right of the layer name (three dots) and then click Duplicate.

Customizing Layers

You can click the title of the layer to select it, and then a variety of options in the layer Properties pane on the right-hand side menu will become active for you to customize the layer.

The layer menu appears to the right of the map when a layer is selected. It has a variety of buttons – from top to bottom, they are:

Properties (like transparency, visibility levels…)
Styles: select and style the attributes you want to map
Filter: filter your map based on attributes to show only certain points
Effects: select from a variety of visual effects you can turn on for the entire layer or certain features (drop shadow, saturation, sepia…)
Aggregation: enable point aggregation for dense maps
Pop-ups: customize the pop-up that appears when a viewer clicks a point on the map
Fields: edit the display names for data fields
and more!

There are a variety of options for you in customizing your layers, depending on the attribute upon which you want to focus. Choose an attribute from the your spreadsheet and play around with how you want to visualize it! ArcGIS Online lets you customize most aspects of the visualization. Click the Styles button in the right-hand layer menu.

You can choose either + Field to map a particular attribute from your spreadsheet or + Expression to write a mathematical script based on your attributes that returns a value (for example, percent of a total).

For textual/categorical data (race, jobs, schooling, heritage…):

Types (Unique symbols), which shows different categories as different colors
Location (Single symbol), which simply shows the location of your data (as a point or as a polygon) The visual aspects (like size, color, symbol, transparency) can be customized by clicking the Style options button.

For numeric data (acreage, ages, number of people in a household, number of grandparents born in Iowa or in the US…):

Counts and Amounts (Size), which uses symbol size to represent your numeric data
Counts and Amounts (Color), which uses a color scheme to represent your numeric data
Color and Size, which allows you to use both symbol size and color scheme
Location (Single symbol), which simply shows the location of your data (as a point or as a polygon)
Types (Unique symbols), which shows different categories as different colors
and for points data, Heat Map, which shows areas of high activity in colors that appear “hotter”

Click the Style options button under the selected drawing style to customize the visualization on your map. Each of the options outlined can be customized – both the visual aspects (like size, color, symbol, transparency) and some of the numeric aspects (such as data classification and breakpoints).

Here’s a simple layer showing the total number of people in any given household:

Using the +Expression button for attribute selection on the layer style pane, it is possible to write a mathematical script that returns a value based on the attributes selected. For example, you could enter ($feature.Female_Under_5+$feature.Fem_5_to_17+$feature.Male_Under_5+$feature.Male_5_to_17) to calculate the number of children under 17 across genders and age groups for a total number of children in a given household:

After selecting an attribute from the dropdown, you can click the + Field button again to add a second attribute, if the two attributes are ones that can be mapped together. You can then customize the appearances of both. If the two attributes you want to map cannot be mapped together on a single layer, you can create multiple layers and adjust their transparencies to show overlap or showcase them in separate map images.

Here’s an example of multiple attributes being mapped at once, with the previous expression, Total Number of Children in Household, represented by the size of the dots, and the number of years married represented by the color of the dots:

Once you’re finished customizing, make sure to click the blue Done button at the bottom of the right-hand viewing pane to make sure your changes are saved.

Let’s reflect:

What do you notice about your visualization as you change its drawing style and customize its appearance?
What is gained and what is lost with different visualization options?

Configuring Pop-Ups

What is a pop-up? A pop-up is the box of descriptive information that appears when a map viewer clicks on a point or feature on a map.

You can configure the pop-ups that appear when a viewer clicks on your data points by clicking the Pop-ups layer menu item on the right-hand side. By default, they show a table with all of the information from that point’s row in your spreadsheet – but some or most of this information may not be needed depending on what you are trying to showcase with your map.

By default, what appears is a Fields list of all your point’s data fields: you can click into this to customize which fields appear.

You can click the + Add content button at the bottom to customize the content that appears. You can add a Text field and customize the text that appears by pulling in specific fields using curly brackets, such as {Field Name}.

You can even pull images and charts into your pop-up, though these need to be created based on your data fields (so a link to an image hosted elsewhere would need to appear in the spreadsheet as a field).

Don’t forget to click the OK button at the bottom of the pane when you’re done customizing your pop-up, to save your changes.

Let’s reflect: how do external map elements like this pop-up influence the viewing experience? How do you think they could or should be used most effectively?

Map Accessibility

After putting time and care into creating your map, you want everyone to be able to view it the way you intend: accessibility is crucial.

What is web accessibility? “Web accessibility is the inclusive practice of ensuring there are no barriers that prevent interaction with, or access to, websites on the World Wide Web by people with physical disabilities, situational disabilities, and socio-economic restrictions on bandwidth and speed.” (Wikipedia). As you create your map, keep accessibility at the forefront of your mind:

be careful in your use of color and ensure appropriate color contrasts and differentiation (basemap, layer colors…)
consider how you can avoid using color alone to convey meaning: vary labels and color, utilize different shapes, change both size and color value of the same shape (source: “Improving Accessibility with ArcGIS Online Web Mapping Apps” presentation from Esri)
be thoughtful about your text content (pop-ups, map descriptions, and more): break up walls of text, ensure appropriate typeface and font size when you are customizing, provide links that make sense out of context (i.e., no “click here”)

You can use these resources to check your work:

check color contrasts with WebAIM’s Contrast Checker
check accessible color selection with Toptal’s Colorblind Web Page Filter, the Color Oracle software, or the Colorblindly Chrome extension

Let’s reflect: what choices do you make as map creators that impact the accessibility of your maps for your viewers? What are some concrete examples of accessible features on a web map? What else do you need to keep in mind?

Next Steps

There are ways to directly share your map with others if you want to. You can do this in a couple of different ways, depending on your needs: one easy way is to click the share button on the left-hand menu of the map. There are several sharing levels:

owner: visible only to you, the creator
organization: visible to all members in our organization, Grinnell College
everyone (public): visible to the wider community outside of Grinnell College

You can very easily a pull an ArcGIS Online map into a StoryMap to provide narrative and context relating to your map. You will still want your map sharing levels to be set to whatever sharing level your StoryMap will be.

It is also possible to create a “shared update” group for sharing, which allows multiple people to work on the same map at once (similar to the collaborative editing features in Office 365). You are not able to create “shared update” groups on your own: this must be done by an admin. To be able to embed your map on an external website, you need to make sure it is set to the “public” sharing setting. Once you have done so, you can click the Embed in Website button to customize your embed settings. Your map does not need to be shared publicly to be shared more widely as a web app – more on that below.

Returning to an Existing Map

Click Content in the top level menu (available when you click the Home button if you are currently viewing a map or other content) to see all your saved content and return to an existing map. Click the title of an existing map, then click the Open in Map Viewer button (top right) to continue editing.

Going Further

Analysis

There are powerful analysis features now enabled by default on all institutional ArcGIS Online accounts. The Publisher account also allows you to host feature layers that can be updated as needed and used across multiple maps. Any users experiencing account issues (for example, if they are not seeing these features because they have an older account) should ask for assistance from an ArcGIS Online admin (Tierney Steelberg or Mo Pelzel) or put in a Help Desk ticket

Some examples of analysis features include:

the ability to “join” one dataset to another using a unique identifier column
the ability to measure distances between points (in a straight line or via selected travel mode)
the ability to analyze patterns
and more!

See more on analysis from Esri’s help documentation: Perform Analysis.

Creating a Web App

What’s a web app? A web app allows you to share a customized and streamlined view of your map with external viewers. Changes made to your map are reflected on its web app version. If you are interested in playing around with this feature and sharing your map as a web app, you can follow these web app instructions from Esri. You can quickly create Instant Apps, using a variety of pre-set options with a quick questionnaire about your goals and visualization needs to help guide you, or you can create a custom app from scratch using the Experience Builder.

Hosted Feature Layers

Hosted feature layers allow you to upload your geospatial data file(s) (spreadsheet, shapefiles, etc.) and host them from within ArcGIS Online. This allows you (and others, if shared publicly) to use them in different ways across multiple maps or web apps, which are then updated automatically when you push updates to the hosted feature layer. For most digital projects, a hosted feature layer is much more efficient than uploading files to the map directly.

To level up your skills, you can play around with hosting the CSV or shapefile data as a hosted layer within ArcGIS Online, rather than adding the file directly to a map. See more information on Hosted layers in Esri’s ArcGIS Online documentation.

Level Up

If you want to level up your mapping skills and go further in your exploration of ArcGIS Online, you can optionally try some of the following:

Download some other Iowa Township Project datasets from this OneDrive folder and try mapping them. There are both CSVs and shapefiles with additional data. Try comparing and contrasting historical data from 1900 and 1920.
Try playing around with some of the Analysis and other Publisher features, once your Publisher account has been enabled. Test out hosting the CSV or shapefile data as a hosted layer within ArcGIS Online, rather than adding the file directly to a map.
Use ArcGIS Online’s browse and search features under the “Add” section to add additional layers of content to your map: you can find data created and curated by a variety of other organizations (such as recent federal census data, for example).
Try building out a StoryMap with additional content to contextualize your map, following these Getting Started instructions from Esri.
Try exploring the new Map Viewer to get a feel for it.
Try creating a web app to streamline your map’s functionality for your users (for example, try out some of the comparison web app features that let you compare two layers or two maps).

Resources

Resources & Documentation

DLAC’s own ArcGIS Online Resources website
ArcGIS Online resources and tutorials from Esri
- Including this “Create maps in Map Viewer” tutorial
ArcGIS Online “getting started” documentation from Esri

Design & Accessibility

Best Practices for Map Design: An Introduction, Leff, Davis-Holland, & Ducey (2016 presentation)
Improving Accessibility with ArcGIS Online Web Mapping Apps (US Department of the Interior, 2019 presentation)

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