He was at Celtic for 15 years between 1922 and 1937, although he did spend the majority of the 1923–24 season on loan at fellow 1st Division side Clydebank. After a spell managing Kilmarnock from December 1937 to July 1945, he became Celtic manager, where he remained for just under 20 years, until March 1965 when he was succeeded by Jock Stein.