During his service in the Corps, Smith conducted surveys of the Great Lakes, the states of Texas, Arizona, and Florida, as well as much of Mexico. While serving in Florida, Smith was stricken with the infectious disease malaria. Although he would recover at the time, the illness affected his physical health for the rest of his life. In 1856 Smith began his involvement in the lighthouse service, which was headquartered in Detroit, Michigan, and eventually rose to become the Engineer Secretary of the Lighthouse Board.