The Dakota Territory legislature created the county on January 4, 1873, naming it for Civil War General Philip Henry Sheridan.

[3][4][5] Sheridan has been severely affected by out-migration; its population collapsed from 7,373 in 1930 to 1,321 by 2010.

[7] The terrain of Sheridan County consists of dry rolling hills, dotted with lakes and ponds.

[8] The terrain slopes to the north and east, with its highest point on the eastern part of its southern boundary at 2,034 ft (620 m) ASL.

[10] (U.S. Census Bureau, n.d.) Race and Ethnicity American Indian and Alaska Native 11; Asian 8; Black or African American 2; Hispanic or Latino 10; White alone, not Hispanic or Latino 1,191; Some Other Race 5; Two or More Races 48 Families and Household Characteristics 2.63 ± 0.29 Average Family Size in Sheridan County, North Dakota Estimate for Average Family Size in Sheridan County, North Dakota.

In terms of ancestry, 70.1% were German, 14.2% were Norwegian, 6.3% were English, 6.0% were Russian, and 1.8% were American.