1903 : New York Highlanders join American League

On March 12, 1903, the New York Highlanders are given the go-ahead by team owners to join baseball's American League. The Highlanders had recently moved from Baltimore, where they were called the Orioles and had a winning tradition dating back to the 1890s. Called the "Yankees" by fans, the team officially changed its name to the New York Yankees in 1913, and went on to become the most dominant franchise in American sports.

It wasn't until 1921, however, that the Yankees won their first American League pennant, behind the prodigious power of right fielder Babe Ruth, who the Yankees had purchased from the Boston franchise, much to the disappointment of Boston fans, in 1920. The team went on to dominate the American League throughout the 1920s, and in 1927, with the "Murderer's Row" lineup of Babe Ruth, Lou Gehrig, Tony Lazerri and Bob Meusel, the Yankees won 110 games and swept the Pittsburgh Pirates in the World Series, 4 games to 0. This 1927 team is still considered the standard by which other teams are measured.

During Ruth's 14-year tenure (1920-1934), the Bronx Bombers won four World Series and lost two. The other major star of Ruth's era was first baseman Lou Gehrig, whose time with the team spanned two generations of Yankee dominance, first under Ruth and later with star center fielder Joe DiMaggio (1936-1951). With DiMaggio, known as the "Yankee Clipper," in center field, New York won nine titles and 10 American League pennants, including four World Series in a row between 1936 and 1939. Gehrig's 2,130 consecutive game streak held for 44 years. He was finally forced to retire in 1939, when he contracted amyotrophic lateral sclerosis, which has since come to be known as "Lou Gehrig's disease."

The 1950s featured a balanced team led by "the Ol' Perfesser," manager Casey Stengel. Under Stengel, the talent-packed Yankees won the World Series each year from 1949 to 1953. By this time, Yankee dominance had begun to inspire resentment among fans of less fortunate teams. In 1955, this antipathy inspired the musical "Damn Yankees," in which a Washington Senators fan sells his soul to the devil so he can slug the Senators to victory over the Yankees and win the pennant. Though the Yankees lost the 1960 World Series, which prompted the firing of Stengel, players continued to turn in all-star performances. In 1961, Roger Maris broke Babe Ruth's record of 60 home runs in a single season with 61 of his own, after a year-long race with friend Mickey Mantle, who ended his season early because of injuries with 54 homers.

In 1977, "Mr. October" Reggie Jackson hit three home runs on three swings in Game 6 of the World Series against the Los Angeles Dodgers to give the Yankees their first World Series since 1962. They repeated in 1978, again beating the Dodgers behind Jackson and pitchers Catfish Hunter and Ron Guidry. By then, the team was owned by George Steinbrenner, whose meddlesome ways, doomed free-agent signings and rivalry with on-again, off-again manager Billy Martin led to a 17-season drought between World Series titles from 1979 to 1996. In 1996, Steinbrenner hired manager Joe Torre and his steady hand, along with the leadership of shortstop and future captain Derek Jeter, guided the Yankees to four World Series championships and six American League pennants between 1996 and 2003, with three World Series wins in a row from 1998 to 2000.

Through the 2010 season, the Yankees had won a record 27 World Series and 40 American League pennants. The record for second-most championships belonged to the St. Louis Cardinals, who had 10.