Primary map (top) only shows primaries, not caucuses or other delegate-selection contests. Convention map based on which candidate got the plurality of votes from each state on the first ballot, before switching. Information from Congressional Quarterly publications.
The 1952 Democratic race for the nomination is an example of how winning the primaries was not always an assurance of the nomination or even a necessary route to the convention the way it is today. Kefauver defeated Truman in New Hampshire, a decisive event showing the president’s weakness (in 1968, McCarthy humiliated Johnson but only by coming in a close second, not an actual win). Kefauver entered and won most of the primaries, which today would have swept him to the nomination easily. But in the past, party leaders controlled the delegate-selection process in most states and the 1952 convention opened with multiple candidates holding significant numbers of delegates, including Kefauver, the Southern faction’s candidate (Russell), the mainline party leaders’ pick (Stevenson), and Harriman with a New York-centered block of delegates. A multi-ballot convention followed, the exciting kind that news reporters now can only fantasize aloud about while they watch the bland made-for-prime-time conventions produced today.
The first presidential ballot still had Kefauver ahead with 340 delegates to Stevenson’s 273, Russell’s 268, Harriman’s 123, and multiple other candidates with 65 or fewer. The second ballot winnowed the favorite-sons and minor contenders as the major factions consolidated; Kefauver had 362 to 324 for Stevenson and 294 for Russell. Harriman still had 121 delegates but he threw his support to Stevenson before the third ballot. A general shift to Stevenson put him over the top. Stevenson had been a reluctant candidate but the choice of Truman and others; Kefauver’s efforts in the primaries had not been rewarded. Stevenson would go on to be defeated by Eisenhower…twice. He still got the "yellow dog Democrat" votes in the South however, despite being a Unitarian intellectual running against a war hero.
Schedule of 1952 primaries from Congressional Quarterly’s Presidential Elections, 1789-1996
March 11: New Hampshire
March 18: Minnesota
April 1: Nebraska, Wisconsin
April 8: Illinois
April 15: New Jersey
April 22: Pennsylvania
April 29: Massachusetts
May 5: Maryland [Democrats]
May 6: Florida [Democrats], Ohio
May 13: West Virginia
May 16: Oregon
June 3: California, South Dakota
June 17: DC [Democrats]
Classic races for the nomination, pre-1972, depicted in maps
Primaries and caucuses 1972 and afterwards