Their departure, earlier reported by The Washington Post, follows complaints from some local women’s march leaders that the New York-based group was too insular to lead a national movement. It comes after two of the earliest organizers of the march on Washington accused Ms. Mallory and a fourth co-chair, Carmen Perez-Jordan, of making anti-Semitic remarks.

Ms. Perez-Jordan, a Latina activist who organizes against mass incarceration, will remain on the Women’s March board.

The four co-chairs helped change the face of American feminism by highlighting the voices of women of color, as well as sexual minorities. But they were also accused of concentrating power in the hands of a small group of New York-based activists.

The group angered some activists in other parts of the country when members tried to trademark the name Women’s March in the wake of the 2017 march, which was put together by loosely connected volunteers, many of whom found one another on Facebook. Millions took to the streets in simultaneous marches in Washington and hundreds of cities around the world.

After the 2017 march, the four co-chairs ousted one of the group’s earliest organizers, Vanessa Wruble, who is Jewish. Ms. Wruble later helped establish a new organization and made accusations of anti-Semitism. Ms. Mallory’s close ties to the Nation of Islam leader Louis Farrakhan, who is respected in the black community, but is widely reviled in the Jewish community for virulently anti-Semitic remarks, had long raised eyebrows in New York.