By 1854, 300 squatters occupied the west bank of the river, and in 1855 Congress recognized the squatters’ right to purchase the land they had claimed. The west side quickly developed scores of new mills and consortia. They built a dam diagonally into the river to the north, which, along with Steele’s dam created the inverted V-shape, still apparent today. Steele created the St. Anthony Falls Water Power Company in 1856 with three New York financiers, Davis, Gebhard and Sanford. The company struggled for several years, due to poor relations with the financiers, a depression, and the Civil War. In 1868 the firm reorganized with new officers including John Pillsbury, Richard and Samuel Chute, Sumner Farnham, and Frederick Butterfield.
As Minneapolis (and its former neighbor across the river, St. Anthony) developed, the water power at the falls became a source of power for several industries. Water power was used by sawmills, textile mills, and flour mills. Millers on the Minneapolis side formed a consortium to extract power by diverting upper-level water into waterwheel-equipped vertical shafts (driven through the limestone bedrock into the soft, underlying sandstone) and then through horizontal tunnels to the falls’ lower level. These shafts and tunnels weakened the limestone and its sandstone foundation, accelerating the falls’ upriver erosion to 26 feet (7.9 m) per year between 1857 and 1868. The falls quickly approached the edge of their limestone cap; once the limestone had completely eroded away, the falls would degenerate into sandstone rapids unsuitable for waterpower. The mills on the St. Anthony (east) side of the river were less-well organized harnessing the power, and therefore industry developed at a slower pace on that side.