The largest run differential in MLB history is with the 1939 New York Yankies with a +441. The largest in recent years is the 1998 Yankies with +309.
The leagues combined in 2000 to form one entity as Major League Baseball.
Washington baseball any league
Walter Young. Baltimore Orioles
Lee Allen has written: 'The American league story' -- subject- s -: American League of Professional Baseball Clubs, Baseball, History 'The hot stove league' -- subject- s -: Baseball, History
Paul G. Zinn has written: 'The major league pennant races of 1916' -- subject(s): Major League Baseball (Organization), Baseball, History 'The major league pennant races of 1916' -- subject(s): Baseball, History, Major League Baseball (Organization)