Complex sentence: The Hull-Ottawa Canadiens were a team in the Ontario Hockey Association (OHA) Senior "A" league for 3 seasons from 1956-59, and in the Eastern Professional Hockey League (EPHL) from 1959-63.
Split into simpler sentences: The Hull-Ottawa Canadiens were a team in the Ontario Hockey Association (OHA) Senior "A" league for 3 seasons from 1956-59. The Canadiens then played in the Eastern Professional Hockey League (EPHL) from 1959-63.