Two months before he turned eighteen, Crookham left his native Ohio for work in Kanawha, Iowa.
Soon after reaching Oskaloosa, Crookham moved near Burlington, Illinois, where he taught school and studied law for a full year.
He began his legal career in Lee County, Iowa, and resettled permanently in Oskaloosa by August 1847.
In March 1855, Crookham was appointed to serve on a commission coveneved by James W. Grimes to select a location for Iowa's capital city.
When Des Moines was chosen, Crookham drove a stake to mark the area in which the Iowa State Capitol would be built.