Before the 20th century, the Illinois River was shallow and much of it was not navigable. In 1848, the Illinois and Michigan Canal was built to connect Lake Michigan to the navigable part of the Illinois River, linking this part of Illinois by water to New York harbor and New Orleans. By the early 20th century, advances in equipment and materials enabled the U.S. Army Corps of Engineers to complete a lock system that transformed the shallow Illinois River into the navigable Illinois Waterway. In 1933, commerce shifted from the Illinois and Michigan Canal to this much larger river-based waterway. Starved Rock Lock and Dam became part of that larger system, one of seven locks forming a water stairway between Lake Michigan and the Mississippi River. Its locks can handle eight barges and a towboat, unlike the one-small-boat-at-a-time locks on the canal. More than 45 million tons of coal, gravel, silica, soybeans, grain, fertilizers, petroleum, iron products, and chemicals pass through here each year.