At the beginning of the Civil War, the federal government excluded Blacks from the army, but in 1862-63, as the need for soldiers grew, the government scrapped the prohibition and welcomed Black soldiers.
- This indicator was developed to encourage inquiry into the significant causes of World War I and the factors leading to U.S. involvement. This indicator was also developed to promote inquiry into the effects of the war, to include its impact on the homefront, migration patterns, and continued foreign policy debates.
- This indicator was developed to encourage inquiry into the causes of American expansion, such as a growing and diversifying population and the expansion of the plantation economy. This indicator promotes inquiry into the relationship between sectionalism and political compromise, culminating in the Civil War.