Whistler was an unincorporated community in Mobile County, until the 1950s when it was annexed into neighboring Prichard. The founding of Whistler, in the 1850s, coincided with construction of the Mobile and Ohio Railroad. The M& O, an early land grant railroad, eventually extended from Mobile to the Ohio River, and beyond to St. Louis, Missouri, and Chicago, Illinois. The town, seven miles north-northwest of Mobile, developed around the M& O shops.