From March 12 to May 17, 1940, voters of the Republican Party chose delegates to nominate a candidate for president at the 1940 Republican National Convention. The nominee was selected at the convention in Philadelphia, Pennsylvania from June 24–28, 1940,. The primaries were contested mainly by Manhattan District Attorney Thomas E. Dewey and Senators Robert A. Taft and Arthur Vandenberg, though only a few states' primaries featured two or more of these men.