In the late 1940s, during the last days of the Dominion of Newfoundland (at the time a dominion-dependency in the Commonwealth and independent of Canada), there was mainstream support, although not majority, for Newfoundland to form an economic union with the United States, thanks to the efforts of the Economic Union Party and significant U.S. investment in Newfoundland stemming from the U.S.-British alliance in World War II. The movement ultimately failed when, in a 1948 referendum, voters narrowly chose to confederate with Canada (the Economic Union Party supported an independent "responsible government" that they would then push toward their goals).

When were the last days of the Dominion of Newfoundland?