Brownsville was created as a lumber camp to supply timber for the Homestake Mine and its buildings and fuel for the boilers. Its founder and contractor, David Brown, also supervised the town's production for several years and supplied much of the equipment. The town was originally called Avalon, but the name was later changed to honor its founder. In 1880, 400 men worked in the town, and the number later grew. The Black Hills & Fort Pierre Railroad built a narrow-gauge spur to the town.