The American Contract Bridge League was founded in 1937. It is the largest bridge organization in the world, with more than 160,000 members living in the United States, Canada, Mexico and Bermuda. A nonprofit organization, the ACBL determines internationally recognized rules of bridge, sanctions clubs and tournament games, and encourages participation at all levels of proficiency and experience. Bridge traces its origins to the British game of whist, first played in the 16th century. It may be named for the Galata Bridge in Istanbul, Turkey, which British soldiers crossed during the Crimean War of the 19th century to reach a coffeehouse where they played cards. Contract bridge, as we know it, began in the 1920s when Harold Vanderbilt came up with the early scoring system.