In the years 1840-1850, which Western state by far had the largest white population?

Indiana

Tennessee

Ohio

Kentucky

The correct answer is: Ohio.

Indeed, because of Ohio's large population which was mostly white; the per capita's part of Ohioans fighting in the Union army was the largest of any Union state. The best three generals of the union army were all from Ohio (Grant, Sherman and Sheridan).

The answer is ohio!