1950s baseball seasons
135 team seasons across 10 years.
1959
- Baltimore Orioles — 41 players
- Boston Red Sox — 41 players
- Chicago Cubs — 39 players
- Chicago White Sox — 40 players
- Cincinnati Reds — 39 players
- Cleveland Indians — 41 players
- Detroit Tigers — 37 players
- Kansas City Athletics — 43 players
- Los Angeles Dodgers — 38 players
- Milwaukee Braves — 37 players
- New York Yankees — 37 players
- Philadelphia Phillies — 37 players
- Pittsburgh Pirates — 37 players
- San Francisco Giants — 34 players
- St. Louis Cardinals — 49 players
- Washington Senators — 40 players
1958
- Baltimore Orioles — 38 players
- Boston Red Sox — 35 players
- Chicago Cubs — 45 players
- Chicago White Sox — 40 players
- Cleveland Indians — 43 players
- Detroit Tigers — 44 players
- Kansas City Athletics — 42 players
- Los Angeles Dodgers — 43 players
- Milwaukee Braves — 35 players
- New York Yankees — 32 players
- Philadelphia Phillies — 41 players
- Pittsburgh Pirates — 36 players
- San Francisco Giants — 39 players
- St. Louis Cardinals — 42 players
- Washington Senators — 39 players
1957
- Baltimore Orioles — 43 players
- Boston Red Sox — 36 players
- Chicago Cubs — 44 players
- Chicago White Sox — 36 players
- Cleveland Indians — 38 players
- Detroit Tigers — 43 players
- Kansas City Athletics — 38 players
- Milwaukee Braves — 39 players
- New York Yankees — 31 players
- Philadelphia Phillies — 35 players
- Pittsburgh Pirates — 40 players
- St. Louis Cardinals — 39 players
- Washington Senators — 41 players
1956
- Baltimore Orioles — 48 players
- Boston Red Sox — 34 players
- Chicago Cubs — 37 players
- Chicago White Sox — 41 players
- Cleveland Indians — 35 players
- Detroit Tigers — 39 players
- Kansas City Athletics — 44 players
- Milwaukee Braves — 33 players
- New York Yankees — 38 players
- Philadelphia Phillies — 37 players
- Pittsburgh Pirates — 42 players
- St. Louis Cardinals — 46 players
- Washington Senators — 33 players
1955
- Baltimore Orioles — 54 players
- Boston Red Sox — 40 players
- Chicago Cubs — 37 players
- Chicago White Sox — 44 players
- Cleveland Indians — 43 players
- Detroit Tigers — 40 players
- Kansas City Athletics — 52 players
- Milwaukee Braves — 32 players
- New York Yankees — 40 players
- Philadelphia Phillies — 44 players
- Pittsburgh Pirates — 42 players
- St. Louis Cardinals — 40 players
- Washington Senators — 40 players
1954
- Baltimore Orioles — 38 players
- Boston Red Sox — 36 players
- Chicago Cubs — 38 players
- Chicago White Sox — 38 players
- Cleveland Indians — 35 players
- Detroit Tigers — 36 players
- Milwaukee Braves — 31 players
- New York Yankees — 39 players
- Philadelphia Athletics — 38 players
- Philadelphia Phillies — 31 players
- Pittsburgh Pirates — 37 players
- St. Louis Cardinals — 36 players
- Washington Senators — 32 players
1953
- Boston Red Sox — 37 players
- Chicago Cubs — 40 players
- Chicago White Sox — 36 players
- Cleveland Indians — 35 players
- Detroit Tigers — 43 players
- Milwaukee Braves — 32 players
- New York Yankees — 37 players
- Philadelphia Athletics — 36 players
- Philadelphia Phillies — 29 players
- Pittsburgh Pirates — 44 players
- St. Louis Browns — 38 players
- St. Louis Cardinals — 41 players
- Washington Senators — 39 players
1952
- Boston Red Sox — 48 players
- Chicago Cubs — 35 players
- Chicago White Sox — 40 players
- Cincinnati Reds — 36 players
- Cleveland Indians — 36 players
- Detroit Tigers — 46 players
- New York Yankees — 38 players
- Philadelphia Athletics — 35 players
- Philadelphia Phillies — 32 players
- Pittsburgh Pirates — 45 players
- St. Louis Browns — 48 players
- St. Louis Cardinals — 41 players
- Washington Senators — 43 players
1951
- Boston Red Sox — 38 players
- Chicago Cubs — 37 players
- Chicago White Sox — 41 players
- Cincinnati Reds — 33 players
- Cleveland Indians — 37 players
- Detroit Tigers — 35 players
- New York Yankees — 41 players
- Philadelphia Athletics — 34 players
- Philadelphia Phillies — 37 players
- Pittsburgh Pirates — 45 players
- St. Louis Browns — 51 players
- St. Louis Cardinals — 45 players
- Washington Senators — 38 players
1950
- Boston Red Sox — 41 players
- Chicago Cubs — 32 players
- Chicago White Sox — 43 players
- Cincinnati Reds — 34 players
- Cleveland Indians — 30 players
- Detroit Tigers — 30 players
- New York Yankees — 38 players
- Philadelphia Athletics — 33 players
- Philadelphia Phillies — 32 players
- Pittsburgh Pirates — 40 players
- St. Louis Browns — 36 players
- St. Louis Cardinals — 40 players
- Washington Senators — 41 players