William Hanchett was born in 1839 in Michigan, the son of Charles (b. 1803) and Abby Ann (Ives, b. 1811).
New York native Charles married Connecticut born Abby in Portage County, Ohio and was living in Portage County in 1830. Charles eventually settled in Michigan sometime before 1839; indeed by 1840 Charles was probably living in Eaton, Eaton County. By 1860 William was living with his family on a farm in Castleton, Barry County. (Charles married his second wife, Lucina Winn Boddy in 1864 in Eaton County, Michigan.)
In any case, William was 22 years old and possibly living in the vicinity of Hastings, Barry County (or in Eaton County), when he enlisted in the Hastings Rifle Company in April of 1861. The company was disbanded shortly after it arrived in Grand Rapids and its members distributed to other companies of the Third Michigan infantry then forming at Cantonment Anderson just south of the city; William eventually enlisted in Company K on May 13, 1861.
He was reported on detached duty serving as a teamster, probably at Brigade headquarters, in July of 1862 and in September. He was a saddler from October through December of 1862, serving with the Brigade wagon train from January of 1863 through July, and a teamster detached with the Third Brigade Quartermaster department from September 19, 1863 through March of 1864. By April he was a clerk at Brigade headquarters, in May he had returned to the Brigade wagon train, and he was mustered out of service on June 20, 1864.
It is not known if William returned to Michigan. He was possibly working as a common laborer and living as a single man in Paisley, Lake County, Oregon; his younger brother (?) James was living in Summer Lake, Lake County, Oregon.
William applied for and received a pension (no. 968721), drawing $6 by 1899.
By 1891 William was living in Arlington, Washington state, and he was living in Adelaide, Kings County, Washington in 1895.