The Interstate League was the name of five different American minor baseball leagues that played intermittently from 1896 through 1952.

Early leagues

Earlier versions of the Interstate League, with years active:

• 1896–1901: an unclassified loop with teams in Ohio, Indiana, Michigan, Kentucky, and West Virginia.
• 1905-08; 1914-16: a Class D league with clubs in Pennsylvania and New York.
• 1913: a Class C league operating in Ohio, Pennsylvania and West Virginia.
• 1932: a Class D circuit based in Pennsylvania and New Jersey.

In addition, a Class C Interstate Association existed for one season, 1906, in Michigan, Indiana and Ohio.

1939–1952

Interstate League

Sport	Baseball
Founded	1939
Inaugural season	1939
Ceased	1952
No. of teams	4 (1939) 8 (1940–1941) (1946–1952) 6 (1942–1945)
Country	United States
Last champion(s)	Hagerstown Braves
Most titles	Wilmington Blue Rocks (4) Lancaster Red Roses (4)
Official website	None

The longest tenured version of the Interstate League was the last incarnation, which played in the Middle Atlantic States from 1939 through 1952, and was one of the few mid-level minor leagues to operate continuously during the World War II period.

This circuit, which began as Class C and was upgraded to Class B in 1940, typically had teams in Allentown, Harrisburg, Lancaster and Sunbury, all in Pennsylvania; Hagerstown, Maryland; Trenton, New Jersey; and Wilmington, Delaware. Its final champion was the Hagerstown Braves, a Boston Braves affiliate. That season, the York White Roses led the league in attendance, attracting over 78,000 fans.

Cities/Teams/Years

League champions

Individual records

Hitting

• Games: 142, Steve Flipowicz, Sunbury (1947)
• Batting Average: .428, Woody Wheaton, Hazelton (1939)
• At Bats: 593, Robert Mays, Hagerstown (1943)
• Runs: 128, Nellie Fox, Lancaster (1945)
  128, Richard Burgett, Allentown (1946)
• Hits: 220, George Kell, Lancaster (1943)
• Runs Batted In: 144, Edward Sanicki, Wilmington (1946)
• Doubles: 52, Bob Maier, Hagerstown (1943)
• Triples: 24, Harold Bamberger, Trenton (1947)
  24, Charley Neal, Lancaster (1951)
• Home Runs: 37, Edward Sanicki, Wilmington (1947)
• Extra Base Hits: 73, John Capra, Allentown (1944)
• Total Bases: 320, Del Ennis, Trenton (1943)
• Consecutive Game Hitting Streak: 22, Harold Nerino, Sunbury (1940)
  22, Bill Cox, Harrisburg (1941)
  22, Edward Nowak, Hagerstown (1945)
• Sacrifices: 24, Harvey Johnson, Harrisburg (1941)
• Stolen Bases: 47, Joseph Schmidt, Wilmington (1946)
• Walks: 130, Guy Glaser, Wilmington (1945)
• Hit By Pitch: 23, Nellie Fox, Lancaster (1945)
• Struck Out: 123, Peyton Rambin, Trenton (1949)

Pitching

• Games: 49, George Eyrich, Wilmington (1948)
• Complete Games: 29, Charles Bowles, Lancaster (1943)
  29, Norman Shope, York (1944)
• Wins: 24, Daniel Lewandowski, Allentown (1951)
• Losses: 21, Wilson Emmerick, Allentown (1943)
• Best Percentage: .880 (22-3), Anderson Bush, Hagerstown (1951)
• Earned Run Average: 1.44, Royce Lint, Harrisburg (1942)
• Innings Pitched: 260, Charles Miller, Hagerstown (1943)
• Win Streak: 13, Woody Wheaton, Lancaster (1943)
• Shutouts: 7, John Burrows, Wilmington (1942),
• Strikeouts: 278, Andy Tomasic, Trenton (1947)
• Bases on Balls: 165, Dick Libby, Sunbury (1948)
• Wild Pitches: 19, Joseph Slotter, Hagerstown (1944)

No-hitters