New major leagues have sprung up throughout the history of baseball, both long-term successes (the American and National leagues), and the transitory, of which the Federal League (1914-15) and the Mexican League (1946) were two. Some leagues were born of noble motives (the Union Association, 1884, to abolish the reserve clause); others, farcical (the Global League, 1969). And many were stillborn, never playing that first inning (such as the Continental League, 1959-60). Here is their history, and an analysis of the conditions that determined their success or failure.