The correct statements about Isaac Stevens are:
- He served in the Mexican-American War.
- He was Washington’s first territorial governor.
- He had the title of Supervisor of Indian Affairs.
Isaac Stevens did not fight for the South during the Civil War; he was a Union general. Additionally, he did not choose Seattle to be the territorial capital, as it was Washington's first territorial governor who made the decision, but Olympia was selected as the capital instead.