1964 Republican Party presidential primaries
From February 15 to June 19, 1964, voters of the Republican Party elected 1,308 delegates to the 1964 Republican National Convention through a series of delegate selection primaries and caucuses, for the purpose of determining the party's nominee for president in the 1964 United States presidential election. United States Senator Barry Goldwater of Arizona was selected as the nominee at the 1964 Republican National Convention held from July 13 to July 16, 1964, in San Francisco, California.
Source: Wikipedia — 1964 Republican Party presidential primaries (CC BY-SA 4.0)