The Philadelphia Athletics were a Major League Baseball team that played in Philadelphia from 1901 to 1954, when they moved to Kansas City, Missouri, and became the Kansas City Athletics. Following another move in 1967, the team became the Oakland Athletics. In 2025 the franchise will move temporarily to Sacramento before permanently moving to Las Vegas.

Major League Baseball (MLB) is a professional baseball league and the highest level of organized baseball in the United States and Canada. One of the big four major leagues, MLB comprises 30 teams, divided equally between the National League (NL) and the American League (AL), with 29 in the United States and 1 in Canada. Formed in 1876 and 1901, respectively, the NL and AL cemented their cooperation with the National Agreement in 1903, making MLB the oldest major professional sports league in the world. They remained legally separate entities until 2000, when they merged into a single organization led by the Commissioner of Baseball. MLB is headquartered in Midtown Manhattan.