The Ancestry Library Edition database offers Census manuscripts from the mid-1800s through 1940. Records from the 1920 and 1930 Censuses were mapped onto the 1922 and 1929 Sanborn basemaps (respectively) using the building footprints created by previous Bednar interns. The results can be found here:
1920 Census Map
1930 Census Map
See below for:
Project Description & Goals (Sanborn+Census)
Relationship Classes & Publishing a Map
ArcGIS Online tools
Project Description & Goals
The aim of this portion of the project was to combine U.S. Census data for State College for the years 1920 and 1930 with building footprints from Sanborn Fire Insurance Maps to create a map product which visualized the location of residents in State College at a household level. The project and product were developed with a few specific goals in mind:
The results of this project showcase the kind of close-scale mapping and research that can be undertaken with University Libraries’ resources.
This project along with the others hosted on this site are made possible by the Marie Bednar Libraries Internship Program Endowment, which provides funds for student internships in various departments throughout the Libraries.
Relationship Classes
In GIS, two datasets (spatial or non-spatial) can be related to each other. This links information from both tables based on a single shared field, called a key field. Relationship Classes are a feature of ArcGIS that allow multiple table entries to be related to a single feature from another table or feature class. This type of relationship is known as a one-to-many relationship. ___
Within a GIS framework, the relationship class allows a user to discover new information that would not otherwise be accessible. For example, a user could select all of the buildings on a block and — with one click — view all of the residents living there. This connection is excellent for increasing the interactivity and information capacity of online maps (such as these) but also has importance for many types of GIS-based analyses.
Tutorial
To create a relationship class between two datasets in ArcGIS, start in ArcCatalog. Make sure the datasets are saved within the same geodatabase, then right-click on the geodatabase and go to ______ New > Relationship Class. (Note: This process requires the datasets to be saved in a geodatabase, not in a regular folder as shapefiles.) _______________________________________ In general, For this project, where the relationship was created between a feature class and a table, the origin will be the ___ and the destination will be ____.
Publishing a Map
ArcGIS Online tools
ArcGIS Online provides tools for sharing maps and allows users to interact with spatial data. If ArcMap is used to relate the Census records to the building footprints, you can publish the result to ArcGIS Online as a feature layer.
Once the feature layer is published, there are two steps needed to create an interactive product. Firstly, the layer needs to be imported to a Web Map. Select “Map” from the “Create” dropdown menu, fill in the information, and press OK. Once the map is opened, “Add” the published layer. The second step is to import the new map into a Web Mapping Application, which allows users to interact with map features more effectively. From the map editor, hit “Share”, select the “Web AppBuilder” tab, and click “Get Started”. Using the AppBuilder, you can change the theme, style, and other attributes of the App interface.
To add the name search feature used in the 1920 and 1930 maps above, go to the “Widget” tab and a new Query widget. Queries are designed to retrieve all relevant results based on either a pre-set or user-defined condition. For the above maps, users were asked to enter the last name of the person they were searching for. To configure this type of Query, follow the steps below:
- Click the edit button on the bottom right corner of the Query icon to open the “Configure Query” window.
- Create a new query and select the building footprint layer as the data source. Be sure to use the layer that is part of the relationship class created earlier.
- Give the Query widget a suitable title, such as “Search for Residents”.
- In the Filters tab, click the gear icon to the right under “Attribute Criteria”. Click “Add a filter expression”.
- Select which field the user can search (e.g. “Surname”). This means that the Query will return any records whose last name matches the specified Surname.
- Check the “Ask for Values” box to allow for user input, and fill in the Prompt and Hint text as appropriate. Click OK.
- Uncheck the box labeled “Display SQL expression for end users”. This option is unnecessary for the simple search function used in this Application.
- (Optional) Under the Results tab, click the “Configure custom content” bubble. Filling in the next two boxes will, respectively, give a title to each returned search record, and specify a subset of Census fields to display. These options improve the appearance of Query results for the user and allow for the display of more returned records at a time if a subset of fields is displayed. In the above maps each record is titled with the resident’s Surname and displays the Surname, First Name, Relationship, Gender, Age, and Full Address fields.
- (Optional) At the bottom of the Configure Query window, enter “Search” in the box for the Tasks tab label. This will make it more obvious to the user that the Query widget is a search function.
- Click OK.
When opened, the fully-configured Query widget should look somewhat like this:
For a full tutorial on configuring this widget, check out this documentation.
(images test)
Related Links:
Penn State University Libraries’ Collection of PA Sanborn Fire Insurance Maps
Ancestry Library Edition (must log in through Penn State or another subscribed institution)