small, fast sailing ship developed by Chesapeake Bay (U.S.) builders in the 18th century. Its speed made it valuable for use as a privateer, for conveying perishables, and in the slave trade, and its hull design gives it claim as an ancestor of the larger clipper ships (clipper ship) of the 19th century. Most Baltimore clippers had two steeply raked masts that were rigged with various combinations of fore-and-aft and square sails.