Union Falls, Saco River, ca. 1910
The owners of Saco Water Power Co. built a stone dam at Union Falls on the Saco River in 1856. The river continued to be important to industry and power generation. York Manufacturing Co., which produced textiles along the Saco River starting in 1833, began Saco Water Power in 1837 to control water power rights for the York Mills. Saco Water Power Co. built the Laconia Mills on the Biddeford side of the river in 1844, and started Pepperell Manufacturing Co. in 1850.