Wilson, a civil rights lawyer who specialized in housing law, was part of the legal team that challenged a restrictive covenant that barred black home-buyers from certain whites-only neighborhoods in Missouri.
The effort led to the landmark 1948 U.S. Supreme Court ruling, Shelley vs. Kraemer, which held that state courts could not constitutionally prevent the sale of homes and businesses to blacks even if the property is covered by an otherwise legal racially restrictive covenant.
She was elected to the national board of the National Assn. for the Advancement of Colored People in 1963 and became chairman of the organization in 1975.
Inside the nation's largest civil rights organization, she and the charismatic executive director, Benjamin L. Hooks, did not get along. In a bitter dispute that became front-page news, Wilson accused Hooks of managerial incompetence after a 25% drop in membership, significant turnover of financial managers and unpaid bills.
After she said he refused to cooperate in an audit of the accounting system, Wilson unilaterally suspended Hooks for insubordination, improper conduct and noncooperation in May 1983. The rest of the board reversed her decision eight days later and then stripped her of all but ceremonial duties.
A month later, she was denied the chairman's traditional right to speak at the NAACP's annual convention. Six months later, as she stood for reelection, the organization placed a dead man on its board rather than let her remain on the 64-member governing body.
By the end of the year, Wilson, who had refused to be called anything but chairman, described the board's actions as sexist.
"We have all had our moments of truth about sexism, about male chauvinism and about disrespect and disregard for women as equals. What has happened to me . . . has been my moment of truth," she said, according to a Washington Post article. "I have not been a person characterized as a feminist or waving the flag of women's rights. I have felt black rights, male and female, were paramount. I don't think this would have happened if I was a male."
Margaret Bush was born Jan. 30, 1919, in St. Louis to parents who were active in the NAACP. She graduated in 1940 from Talladega College in Alabama. She received a law degree from the new all-black Lincoln University law school in Jefferson City, Mo., in 1943, becoming the second woman of color licensed to practice law in the state.
She worked for the federal Rural Electrification Administration, married and returned to St. Louis to start a law firm with her husband, Robert E. Wilson Jr. They later divorced.
Margaret Wilson's father, a railway postal clerk who became a real estate agent, represented a black family in the purchase of a home in a whites-only neighborhood about that time. When the sale was blocked by courts because of a restrictive covenant, the case became Shelley vs. Kraemer. Wilson was the lawyer for the Real Estate Brokers Assn., which was formed at her father's initiative to take the case to the U.S. Supreme Court. The case upended state enforcement of such covenants.
In 1948, Wilson became the first black woman in Missouri to run for Congress. She ran with the Progressive Party of Henry Wallace, lost the race and later joined the Democratic Party.
A year after the Supreme Court handed down its landmark Brown vs. the Board of Education ruling in 1954, outlawing segregation in public schools, Wilson's 5-year-old son entered one of the first integrated schools in St. Louis.
Wilson rose quickly through the presidencies of the St. Louis and Missouri chapters of the NAACP in the late 1950s and early 1960s, when activists began demonstrating in front of a local bank and eventually forced St. Louis businesses to begin hiring blacks for previously all-white jobs.
After she was ousted from the NAACP leadership, Wilson returned to St. Louis and continued to practice law until her death.
Survivors include a son.
Sullivan writes for the Washington Post.