Born at Heath, Massachusetts, in 1831, but who later moved westward to Iowa in search of fortune. John H. Leavitt was the son of Col. Roger Hooker Leavitt, a businessman, politician and noted Massachusetts abolitionist. Young Leavitt studied civil engineering, and early in his career was contracted by John Roebling, the builder of the Brooklyn Bridge, to survey a large tract of land. Having gained some measure of confidence in his abilities, Leavitt struck out for the west in 1854, reaching Dubuque, Iowa, where he remained for less than a year before settling at Waterloo, Iowa. While in Dubuque, Leavitt married Caroline Clark Ware of Granville, Illinois. Shortly after his move to Waterloo, the young engineer decided on a change of career, and became a banker. Within a decade he founded his own private banking firm. In 1871, Leavitt was elected to the Iowa Senate, where he was engaged in the fight to prevent the return of James Harlan to the United States Senate after his service as a member of Abraham Lincoln's cabinet. A staunch Republican, Leavitt served only one term in the Iowa State Senate. After leaving the state senate, Leavitt devoted his time to his business affairs, as well as his membership in the Congregational Church of Waterloo. He was an early benefactor of Talladega College, Alabama's oldest historically black college, and in 1903 he joined the Pocumtuck Valley Memorial Association in Deerfield, Massachusetts.