United States Lines was an American shipping company founded in 1932, primarily known for its transatlantic passenger and cargo services. The company operated a fleet of ocean liners, including the famous SS United States, which was launched in 1952 and became one of the fastest passenger ships ever built. The company faced financial difficulties in the 1970s due to rising fuel costs and competition from air travel. It eventually ceased operations in 1986, marking the end of an era for American passenger shipping. Despite its closure, United States Lines remains a significant part of maritime history.