If you look on Wikipedia, or for that matter on almost any website that mentions it, including the official USCF website and the site of the US Chess Trust, You will notice that all these places honor Adele Rivero as the first official U.S. Women's Chess Champion for having won the first tournament organized for that purpose in 1937.
Inconceivably, perhaps, all these places are perhaps completely wrong.
Contemporary sources indicate that the first official U.S. Women's Chess Champion was Mona May Karff who won the first tournament designed to establish such a title in 1938. Adele Rivero would not become an official U.S. Women's Champion until 1940.
Adele Rivero - 1936
Mona May Karff
Adele Rivero playing Mona May Karff (a.k.a. N. May Karff) in 1942
In 1904 and Carrie Kraus received an unexpected Christmas present. She met the man of her dreams. The New Year brought her a new name - Mrs. Frank James Marshall when, on January 5th, she married the man who a year later would be the premier chess player of the United States. It was perfect union. Caroline or Carrie as she was usually called, was pragmatic; Frank was a dreamer. In 1915 Frank Marshall founded the Marshall Chess Divan which seven years later would be incorporated as the Marshall Chess Club. The Club found itself in various sites over the years but in 1931 it reached its permanent home in a magnificent old brownstone located at 23 West 10th Street, N.Y. By this time, Marshall had retired from international chess and was close to hanging up his U. S. chess champion crown which he had worn since 1909.
The American chess scene itself was in a state of flux and confusion. FIDE had established itself tenuously as the worldwide governing body of chess in 1924. Unlike the Soviet Union, the United States recognized FIDE, but America itself had no single, unified chess federation. Both the American Chess Federation (ACF), which could trace its roots back to 1900, and the National Chess Federation (NCF), established in 1927, claimed to speak for the American chess players. While much of the problem would be solved when they unified as the United States Chess Federation (USCF) in 1939, the intervening years would be marked by the contention between these two bodies.
The Western Chess Association had held tournaments, called the Western Championships, each year since 1900. Then in 1934, it changed its name to the ACF. The Western Championships evolved into what today is called the U. S. Open. The "Chess Review" magazine, founded by Israel Albert (Al) Horowitz and Isaac Kashdan in 1933, was the "Official Organ of the American Chess Federation." When Frank Marshall retired from U.S. chess competition in 1936, he organized an invitational tournament specifically to determine the next U. S. chess champion. This tournament was sponsored by the NCF with the Marshall Club providing the trophy.
The Marshall Club, whose members were the wealthy, the influential and the elite, was, like most chess venues, a Men's Club. But fortunately Caroline Marshall took an active interest in the club. One of her agendas was the establishment, not just of organized women's chess, but of a women's championship. Starting in 1934 with the first women's tournament of this period held in the Marshall Club, the goal of a U. S. Women's championship was reached in 1938.
The first tournament, held in 1934, was won by Marjorie Seaman who breezed through with a perfect 11-0 score. Adele Rivero came in second with a 9-2 score. The 1935 tournament planned in the Fall had to be postponed until Spring of the following year. Adele Rivero won that 1936 tournament with a 5-0 score.
The first two tournaments were sponsored solely by the Marshall Chess Club, but the 1937 tournament was to be held under the auspices of the National Chess Federation itself with the intention of legitimizing it as a national championship.
In 1936 the plans for the 1937 Marshall Club women's tournament included hopes that the winner would be the officially recognized leading woman player in the U. S. and that, as such, would be sent to participate as America's representative to the International Ladies Tournament in Stockholm, basically the women's world championship, that summer. Those dreams were only partially realized.
According to the preeminent women's chess chronicler of that time, Edith Weart, after Adele won the 1937 tournament, "As the tournament this year was sponsored by the National Chess Federation, Mrs. Rivero now holds the title of woman champion of that organization." You may notice there is absolutely no mention of "U.S. Women's Chess Champion." In fact, the following year, Edith Weart wrote: "Feminine chess takes a step forward with the announcement by the National Chess Federation that a tournament will be held in connection with the regular U. S. Championship tournament to determine the U. S. Woman Chess Champion." This clearly indicated that the 1938 tournament, which was eventually won by Mona May Karff, was the first "title tournament."
Also, Adele Rivero, the winner of the 1937 tournament didn't go to Stockholm. Mary Bain, who came in second, went in her place. The event was, of course, won by Vera Menchik.
The preliminaries for the 1938 tournament were to be held in March. In the February 1938 issue of "Chess Review", Ms. Weart wrote: "Added interest is attached to the preliminaries, because they serve as a qualifying tourney not only for the Marshall C. C. Tournament, but, as well for the U. S. Women's Championship." Again, this makes obvious the fact that 1938 was to be the first year the tournament would be played for the national title.
The question remains about what happened to the plan to make the winner of the 1937 tournament the U.S. Women's Chess Champion. It seems that the right of the National Chess Federation's right to determine the U.S. Women's Chess Champion wasn't fully accepted and, for that reason, the winner of the 1937 ACF title was invited to participate.
The winner of the 1937 ACF tournament was Jean Moore Grau of Muscatine, Ohio. Mrs. Grau had the unusual distinction of having drawn against Alekhine in a blindfold simul when she was 17. Grau proved unable or unwilling to make the arduous journey east but proposed that she would like to meet the NCF winner someplace midway for a match to determine the best female player in the U.S. This was agreeable especially since then the title would be the result of a consolidated effort. This match, however, never materialized and the invitation, even unaccepted, to participate in the 1938 tournament seemed to satisfy both organizations enough to declare that the winner of that tournament would be the U.S. Women's Chess Champion.