Even when looking at art they can't forget the race wars...
Bingham was was pro-union during the Civil War. I don't know what they expect. I live 150 years after Bingham and my life is pretty much populated by white people. According to Wikipedia these are my county's demographics:
[The racial makeup of the county was 94.91% White, 3.69% Black or African American, 0.20% Native American, 0.16% Asian, 0.02% Pacific Islander, 0.30% from other races, and 0.72% from two or more races. 1.02% of the population were Hispanic or Latino of any race. 45.1% were of American, 9.8% Irish, 9.7% English and 9.5% German ancestry according to Census 2000.]
Of course, I can watch them on TV.
St Louis which sits at the conjunction of the Missouri, Illinois and Mississippi Rivers was a center of the voyageur Fur Trade. Bingham drew pictures with a cast of characters unrivaled anywhere else in North America.
The half breed Metis culture founded the Illinois Country in the late 1600's. Indians, free and bound metis indians, free and bound negroes, Spanish, Mexicans, and Mestizos trading with Santa Fe, French Canadian and East Coast American English immigrants, - all part of the Illinois Country River world.
Bingham drew what he saw and knew.