For a long time the National League and American League were collectively known as he major leagues, or just the majors, and the head of it all was the baseball commissioner.
I suppose to conform with the NFL, NHL,and NBA, the enterprise is now known as MLB.
In what year did the majors officially become Major League Baseball?
I would say in 1903, with the national agreement signed between the AL and NL, and the creation of the World Series.
Upon further review, the 2005 MLB Constitution does indeed refer to Major League Baseball. However, the 1921 Constitution 1921 Major League Agreement
to which the 2005 Constitution refers, does NOT use the term Major League Baseball, so it is doubtful that the 1903 agreement used it either. So perhaps the date I am looking for is 2005.
Upon even further review, the 1903 agreement uses the term Major Leagues, but not Major League Baseball.
Major League Baseball had their logo at least as early as 1969, with “Major League Baseball” in it, so it wasn’t any later than then.