The Aerial Lift Bridge is a landmark in the port city of Duluth, Minnesota. The span began life in 1905 as the United States' first transporter bridge. . In 1929 - 30, the span was converted to a vertical lift bridge, and continues to operate today. The bridge was added to the National Register of Historic Places on May 22, 1973. The United States Army Corps of Engineers maintains a nearby maritime museum.Bridge historyThe bridge spans the Duluth Ship Canal, which was put through the miles-long sand spit named Minnesota Point (commonly referred to as Park Point by locals) in 1870–71. The natural mouth of the Saint Louis River is about seven miles (11 km) farther southeast, and is split between Minnesota and Wisconsin. Creating this gap in the tiny peninsula meant that residents who lived on the new island needed to have a way to get across. Several transportation methods were tried, though they were complicated by the weather. Ferries could work in the summer, but ice caused problems in colder months. A swinging footbridge was used, but was considered rather rickety and unsafe.In 1892, a contest was held to find a solution. The winning design came from John Low Waddell, who drew up plans for a high-rise vertical lift bridge. The city of Duluth was eager to build the bridge, which would have been about 130 feet (40 m) wide. However, the War Department objected to the design, and the project was canceled before it could be built. Waddell's design went on to be built in Chicago, Illinois, as the slightly larger South Halsted Street Bridge (removed in 1932).
