Title

The demographics

One way to examine the migration of African Americans north in the decades between 1900 and 1930 is to look at the actual change in population on a state-by-state basis. In this activity you are going to use available census data and your GIS software to do just that as you consider:

  • • how the Great Migration affected the relative size of the African American populations in each of the southern states from 1900 to 1930?

    • which states were affected most dramatically by the migration

    • how changes in the southern farm economy were related to the Great Migration

An Example to Get You Started -

Let's first consider the change in the African American population in the southern states as a result of the migration.

Load your GIS software and open the Great Migration project file. Check to see that the United States 1900 and the Southern States 1900 layers are open. You can switch the other layers off. You are going to determine the percentage of the African American population in 1900 for each southern state and present this information in a data map.

Look first at the list of census categories in the Demographics worksheet. Notice that the percentage you want to examine is not a part of the list. You will need to do some simple arithmetic - dividing the NEGRO population by the POP1900 of each state to obtain the percentage that you want. Follow the help steps below in carrying out the calculations.


My World
ArcGIS

• Click on the Analyze tab, select to Add Field(s) By Math Operation, and complete the form as follows:

• Next, double check to see that the new % Negro Population field has been added -

Select the Southern States 1900 layer, click on the table icon ( ) and move the slider at the bottom of the screen all of the way to the right to see the new field:

• Finally, click on the Visualize tab and double click on the Southern States - 1900 layer to bring up the Edit Appearance window. You can choose the Colorscheme you want to use. Enter 5 as the Number of Fill Colors and select to Classify By: Quantiles. This will give you five groups with approximately the same number of states per group:

• Click Apply

 

• Right click the Southern States 1900 layer in the table of contents and select Properties....

• Click on the Symbology tab and select Quantities.

• In the Fields pane select NEGRO as the Value andPOP1900 as the Normalization value.

The result is the desired division. It is said to be a normalized value because we now have a rate that is not affected by the size of the states.

• In the Classification pane click the Classify button. You will see a new window. Select to classify by Quantiles and 5 classes as pictured below:

This will give you five groups with approximately the same number of states per group.

• Click c

• You can define your own labels to make the map easier to read by editing the values in the Labels column:

• Click OK


Once the data is available it is easy to prepare a map of the results like the one below.

My World
ArcGIS

• Select File >> Layout & Print from the main menu.

• Uncheck the Show Scale and Show Compass boxes in this case.

• Click Print

• My World prints an image of the map to a file. Name the file and Save it where you can get to it from your word processor.

• Click on the Apply button and Close the window.

• Select View >> Layout View from the main menu.

• A map template is provided for you to edit. Double click on:

- Map Title to enter your own title
- Created by to add your name and today's date

• Zoom in () and/or pan () to position the map image as desired.

• Select File >> Print from the main menu. Check to see that the correct printer is selected and that the orientation of the map is correct.

• Click OK to print your map.

• Select View >> Data View from the main menu.



Your turn. Prepare a similar map for 1940. You will go through the same steps except that this time you need to define the same classification scheme as in the previous map. This will allow you to examine the results on a comparable county-by-county basis.

My World
ArcGIS

• Click on the Analyze tab and set up the division to create the new percentage as you did for the 1930 data.

• Double click on the Dust Bowl Counties Census Data - 1940 layer to bring up the Edit Appearance window and copy the settings from the Dust Bowl Counties Census Data - 1930 layer. Double click on values in the To column to copy values from the other layer. Values in the From column will be automatically adjusted:

• Click

• Click on the Apply button and Close the window.

• Right click the Great Plains States 1940 layer in the table of contents and select Properties....

• Click on the Symbology tab and select Quantities.

• Click on the Import button and select to Import symbology from the Census 1930 layer:

• Click OK

• Click

Select View >> Data View from the main menu.


To Start You Thinking -

  • 1) Which southern state(s) had a black population that was approximately 47-58% of the total population in 1900?

    2) Which southern state(s) had the greatest percentage of black population in 1900? the least?

    3) Generally speaking, what happens to the percentage of the black population in 1900 as you move from south to north in the map? Identify any exceptions to this generalization.

    4) Compare the two maps. In which state(s) was there an apparent decrease in the percentage of the black population from 1900 to 1930?

    5) In which states was the change in the percentage of the black population the most dramatic? the least?

Complete the Demographics worksheet.

Last modified in October, 2011 by Rick Thomas