The City Series was the name of a series of baseball games played between Major League Baseball's Philadelphia Athletics of the American League and Philadelphia Phillies of the National League that ran from 1903 through 1955. After the A's move to Kansas City in 1955, the City Series rivalry came to an end. The teams have since faced each other in Interleague play (since its introduction in 1997) but the rivalry has effectively died in the intervening years since the A's left Philadelphia.
The first City Series was held in 1883 between the Phillies and American Association Philadelphia Athletics. When the Athletics first joined the American League, the two teams played each other in a spring and fall series. No City Series was held in 1901 and 1902 due to legal warring between the NL and AL.
The rivalry started almost immediately at the establishment of the American League in 1901. Superstar Nap Lajoie had played for several years on the Phillies, but was displeased with the salary cap of $2,400 placed by the National League. So when the Athletics were established, Lajoie quit the Phillies and signed with the A's. In response, the Phillies filed an injunction lawsuit preventing Lajoie from playing on any other team, but the case was ruled that Lajoie was only barred from playing in Pennsylvania. Due to the lawsuit, Lajoie was sent to the Cleveland Bluebirds due to the financial assistance Cleveland had provided for the A's early on. In 1903, the injunction was dropped when the NL and AL made peace. Lajoie went on to have an outstanding Hall of Fame career. Eventually, he did return to the A's at the twilight of his career.
The first City Series game was played on April 9, 1903 at Baker Bowl. The Phillies won 6-5 in ten innings. The Phillies and A's played both a spring and fall series in 1903. The Phillies took four of five games in the spring. With Baker Bowl in disrepair following the collapse of a section of bleachers on August 8, 1903, all of the post-season games were played at Columbia Park. The A's won four of the seven games.