Laurel's earliest mill was established on land originally inhabited by Native Americans along the Patuxent River at the fall line, where changes in the river's elevation provided excellent water power. A massive dam built in 1850 controlled the river's flow to supply water to the Laurel Cotton Mill; according to newspaper reports in 1855, the dam measured 222 feet wide and 27 feet tall. On the south bank, a canal called the mill race ran about 600 feet and directed water into the mill, while wooden doors in a large sluice gate across the channel were opened or closed according to the power needed. Water from the race or canal powered two overshot wheels and later a large Boyden Turbine before flowing back into the river. The dam frequently needed repairs, and most of it was blown up in the 1940s.