Despite the succession of long depressions set off in 1837 and 1843 and a reduction of the toll to 50¢ per ton in 1842, the company remained highly profitable, and the buyout was completed in 1855. By the 1850s, around 40% of the steamboats on the Ohio were too large for the canal and required transshipment of their cargo around the Falls. Despite holding full ownership of the company after 1855, the federal government found it impossible to get Congress to approve taking formal control of the canal. Bills offered from 1854 to 1860 failed on grounds of constitutionality, economy, and efficiency. Lazarus Powell (D-KY) was of the opinion that "the only reason why the government of the United States has not long taken charge of the canal, is the fear that there would be demand on the national treasury to Enlarge it", a reasonable fear given the reasons for the buyout of the original owners. In the end, the government simply directed the company to finance the needful improvements on its own. A $865,000 plan was approved and undertaken in 1860 but was almost immediately shelved by the Civil War. The facility was a target of Confederate forces in Kentucky, at least one of whom advocated destroying it so "future travelers would hardly know where it was", but Union control of the state rendered the threat moot. The loans involved in the original plan, however, meant that the company was $1.6 million in debt by 1866. Radical Republican control of Congress meant that the Army Corps of Engineers was finally allowed to take over improvements for the canal in 1867. Two new locks, each long and wide, opened in February 1872. In May 1874, Congress passed a bill allowing the Corps of Engineers to take full control of the canal and authorizing the Treasury to pay off the bonds for the recent improvements. By 1877, despite the vastly increased use of railroads, traffic on the canal had tripled from any previous level. This was mostly heavy, low-value industrial supplies such as coal, salt, and iron ore. In 1880, under political pressure from upriver producers, Congress removed the canal's tolls entirely, forgoing profit and paying the entirety of its expenses from the Treasury. A new lock was built in 1921 as a part of Congress's plan for the "canalization" of the Ohio River. Further expansions in 1962, increasing the width of the canal to , caused the canal to be known as the McAlpine Locks and Dam.