The Major League Baseball relocations of the 1950s–1960s brought several Major League Baseball franchises to the Western and Southern United States, expanding the league's geographical reach. This was in stark contrast to the early years of modern baseball, when the American League placed teams in National League cities. Chicago, Boston, Philadelphia, and St. Louis had two teams; New York City had three. With no teams west of St. Louis or south of Washington, D.C., baseball was effectively confined to the Northeast and Midwest.
Baseball's expansion mirrored the westward movement of the U.S. population during a flourishing postwar economy that saw the arrival of commercial jet travel. Economic push and pull factors caused many teams to move, and the emergence of cities in the new frontier allowed baseball teams to pop up across the country. The moves of the Brooklyn Dodgers and New York Giants to California in 1958 opened the West Coast to the market of baseball.
