In 1852, Sandwich pioneer William Patten returned from the gold fields of California with $2,000, a fortune at the time. With the coming of the Railroad in 1853, his son Robert Patten, a carpenter, built the town's first lumberyard and a steam gristmill completed in 1856, made possible by investment from his father and land donated by Sandwich founder Alton Gate. The Sandwich steam gristmill produced 100 bags of flour each day, making it a vital part of community life. In 1871, one of Patten's partners absconded with funds and left the business and Patten in great debt. The Robert Patten family left for Kansas, and the business continued under new ownership. The three-story limestone building was equipped with a 65 horsepower steam engine in the basement, increased to 80 horsepower in 1891, that could power three sets of centrifugal reels, separators, purifier dust collector, and storage bins. In 1879, a local newspaper reported flour production as high as 500 bags being shipped as far as Glasgow, Scotland. The mill closed in 1892 and the machinery was removed. Twice in 1902 someone tried to burn the building. It was later used as a machine shop, a farm equipment parts manufacturer, and for storage. In 1964, James Knights donated the building to the Sandwich Historical Society for a museum, which opened in 1969 and continued to safeguard the legacy of Sandwich, Illinois.