The game of baseball in the United States is the oldest major league sport in the country. Major League Baseball traces its roots back to the 1880s, but the game had been enjoyed by Americans for decades before then. The origins of the game are in question. For many years a 19th Century American named Abner Doubleday was credited with creating the game, but this has been proven inaccurate today.
One theory is that the game was brought across the Atlantic Ocean during the great European migration of the 18th Century, and that it is based on the British game of cricket. Cricket is a very popular sport in England, but it is played by mostly the upper-class members of that society, and it is unlikely that the poor immigrants from England played the game very much. However, it more closely resembles the game of rounders, which is another English sport that shares many common features as the American game of baseball.
In any event, the game became very popular in the United States. By the 20th Century, the American League, and the National League were taking the country by storm. The greatest single team in either league's history is the New York Yankees. The Yankees have won more World Series titles than any other team in history.
The World Series is a seven-game competition with the two top teams from either league. The first team to win four games is declared the World Series Champion. In 1903, The Boston Americans won the first World Series beating the Pittsburgh Pirates. This was the start of an annual series matchup between the two leagues. To date, the Yankees have won 27 championships in 40 appearances, with the team's most recent title coming in 2009. The St. Louis Cardinals lead the National League with 11 titles in 19 appearances, with its last title coming in 2011.