Harper moved to Iowa from Ohio in 1842. He represented Des Moines County in Iowa's 3rd and 13th General Assemblies (1850, 1870-1872). During the Civil War he was a successful recruiter which allowed Des Moines County to avoid the draft. In 1877 he moved to Mediapolis, Iowa where he organized the State Bank of Mediapolis and was active in the real estate and insurance fields.
From the description of William Harper correspondence with James Harlan, 1898. (State Historical Society of Iowa, Library). WorldCat record id: 653517269