The land on which Hancock was built was originally owned by James Hicks.
The earliest building in what is now the City of Hancock was a log cabin erected in 1846 on the site of the Ruggles Mining Claim; it is no longer standing, the site taken up by the Houghton County Garage buildings. It was owned by Christopher Columbus (C.C.) Douglass, who came to live there in 1852. The Quincy Mining Company founded Hancock in 1859 after purchasing land from Douglass and building an office and mine on the site. The city was named after John Hancock, signer of the Declaration of Independence.
Hancock's first store was built by the Leopold brothers in 1858; the store also housed the first post office. Samuel W. Hill, an agent for the Quincy Mining Company, platted Hancock Village in 1859. Although it was organized and officers elected in 1863, the village was not incorporated until 1875 under a charter amended in 1877.
In 1860, the Portage Lake smelter opened in Hancock.
In 1869 a fire burnt down about 75% of the village. There was also a significant fire in the 1940s that destroyed much of the downtown.
The Mineral Range Railroad began providing passenger and freight service between Hancock and Calumet in 1873.
Hancock was incorporated as a city in 1903.