For years, gay rights organizations and major civil rights organizations viewed each other warily. African-American leaders often saw the gay rights groups as insensitive to racial concerns, and some resented the movement’s use of civil rights language to make the case for same-sex marriage. Advocates for gay rights, in turn, sometimes blamed socially conservative African-Americans for their defeat in crucial electoral battles.

But since the relationship reached something of a crisis with the passage of Proposition 8, California’s ballot initiative against same-sex marriage, in 2008, leaders in both movements have made an effort to bring their groups closer together.

Now, conversations among leaders in the gay, black and Latino communities have borne significant fruit: On May 19, the board of the N.A.A.C.P. voted to endorse same-sex marriage.

And then, last Tuesday, representatives of several national gay rights organizations gathered at New York City’s Stonewall Inn, often described as the birthplace of their movement, to announce that they would march to protest the New York Police Department’s stop-and-frisk practice, under which the police each year have been stopping hundreds of thousands of New Yorkers, most of them black or Latino, in an effort to prevent crime.