Born in Tennessee in 1797, Gehon lived in Kentucky and Illinois during his early years.
[1] He operated a trading post in Helena, Arkansas before moving to Dodgeville, Wisconsin.
He commanded a militia company in Wisconsin (then part of Michigan Territory) during the Black Hawk War.
[3] In 1839, Gehon was elected the delegate from Iowa Territory to the United States House of Representatives,[4] but never took office.
[2][5] Gehon was offered command of a company of dragoons raised for the Mexican–American War, but declined because of ill health.