 The CFL was officially named on January 19, 1958, upon the merger between the Interprovincial Rugby Football Union or "Big Four" (founded in 1907) and the Western Interprovincial Football Union (founded in 1936).Before the introduction of interlocking play in 1961, teams only competed against each other in pre-season and the Grey Cup Championship (similar to Major League Baseball in the United States).Rugby football began to be played in Canada in the 1860s, and many of the first Canadian football teams played under the auspices of the Canadian Rugby Football Union (CRFU), founded in 1884.