He worked as a teacher for a time, and eventually moved to Kenosha, Wisconsin, then named Southport, where he founded an academy.

Lewis entered into correspondence with a local society called the "Boannergians," in the Summer of 1841 at Western Reserve College in Hudson, Ohio and it became a chapter of Beta Theta Pi on August 9, 1841.

In 1847, Harvey married Cordelia Perrine and they moved to Clinton in Rock County, Wisconsin, then to the nearby hamlet of Shopiere.

In April 1862, having served only a few months as governor, Harvey organized an expedition to bring medical supplies to Wisconsin troops, wounded in the Battle of Shiloh, who were being cared for in hospital boats on the Mississippi and Tennessee Rivers.

Late that evening, while trying to step from a tethered boat to a moving steamboat headed back north (a common but dangerous practice), Harvey fell into the Tennessee River and drowned, despite the strenuous rescue efforts of members of his party.