After the WHL folded and the Stanley Cup was awarded only to the NHL playoff champion, the Prince of Wales Trophy was awarded to the regular season champion. From 1927–28 onwards it was awarded to the champion of the NHL American Division while the O'Brien Trophy was awarded to the NHL Canadian Division. It was then repurposed to being the trophy for the overall regular season champion in the 1938-39 NHL season when the NHL reverted to a single division.