to complete the canal by 1838. About the same time, Congress had the Corps of Engineers (Corps) review the situation. It was recognized that the work would not only include a canal at Portage, but improvements along the length of both rivers between their mouths and the canal. In 1837 and 1839, the Corps examined the waterway's feasibility and recommended a "slack-water" (lock and dam) system. After numerous memorials from the territorial legislature, Congress authorized a land grant for the waterway project in 1846. There were various private companies formed to promote and build the Waterway; besides the Summit Portage company, there were the Fox and Wisconsin Improvement and the Green Bay and Mississippi Canal Companies. In 1872, the Corps assumed supervision of the waterway. Lower Wisconsin Along the Lower Wisconsin there were initially no plans for improvements other than dredging and the clearing of snags. This soon proved to be inadequate. In 1868, the Corps began to experiment with wing dams and dredging to sluice out a 6-foot (1.8 m) deep channel. By 1880, the Corps had completed 157 dams totaling over , mainly in two sections: between Portage and Prairie du Sac and between Lone Rock and Boscobel. But the wing dams also proved inadequate and steamboats were not willing to risk the passage. In 1887, the Corps recommended to stop this method of improvement, effectively closing the Lower Wisconsin to commercial traffic. Accordingly, little commercial traffic was ever maintained along this reach of the Waterway. In 1914 the Prairie du Sac hydroelectric plant was completed creating Lake Wisconsin. This dam marks the lowest of a string of hydroelectric and recreational dams that extend up the Upper Wisconsin almost to its headwaters. The Portage Construction initiated along the Portage Canal in 1849 and finished in 1851. In 1856, the first steamship from the Mississippi, the Aquila, passed through the Portage on its way to Green Bay, signaling the opening of the waterway. The lock and canal were improved several times, culminating in the construction of a concrete structure in 1928. There was a guard lock on the Wisconsin (Portage Lock) and a lifting lock to lower boats to the Fox (Fort Winnebago Lock). Each lock was long and wide. Eventually, as in other parts of the Waterway, traffic dropped off and generally included only pleasure craft. By 1900 there was virtually no traffic to the east to Montello.