The victory of Sloane Stephens in the 2017 singles competition of the U. S. Open made her only the fourth African American woman to win a “major” tennis tournament.

When Americans began playing tennis regularly in the United States in the early years of the 20th century, the sport’s Caucasian organizers would not allow African Americans to play in the tournaments.

That changed in 1950 when the United States Tennis Association, which governs the sport in this country, let Althea Gibson compete in the U.S. national championship event (which became known as the “U.S. Open” only in 1968).

In 1956,...