Marion Wade Doyle, 90, a member of the D.C. school board from 1928 until she resigned in 1949, and its president from 1935 until the end of her service, died of a heart ailment Jan. 8 at her home in Washington.

Mrs. Doyle's service on the school board was the longest and most visible facet of a career in civic and public works that included a term as executive vice president of the national League of Women Voters and the chairmanship of the D.C. commission for the 1960 White House Conference on Children and Youth. As a young woman, she marched in behalf of women's suffrage.

When she announced that she was leaving the school board, The Washington Post said in an editorial that she had "worked tirelessly to improve not merely the schools in this city, but also the full area of educational activity. . . . No single person knows Washington better than she, and none has done more valiant work to build a better city."

Mrs. Doyle, a teacher by training, was fond of noting that in 1805, Thomas Jefferson became the first president of the first board of trustees of the Washington school system, and that he took the post out of a commitment to education. In her day, members of the board were appointed by the judges of the U.S. District Court for the District of Columbia. The board members elected one of their own number to be president. Mrs. Doyle was the first woman to hold the post.

During her years on the board, Mrs. Doyle was guided by her conviction that teachers are more important than buildings and that teachers and school buildings exist to serve students.

To this end, she worked to improve teacher salaries and benefits and to persuade Congress, which then had sole responsibility for the D.C. budget, to provide money for classrooms to house a steadily growing school population. When she was appointed to the board in 1928, the system had 73,157 students, of whom 48,585 were white and 24,772 were black. When she resigned, there were 91,219 students, of whom 47,955 were white and 43,264 were black.

Although the schools here were segregated by law, Mrs. Doyle was known as an opponent of segregation and as an advocate of improved opportunities for blacks.

On matters of curriculum, she took the Jeffersonian view that a well-informed citizenry is the best guarantee of democracy. Thus, in 1935, she opposed a "red rider" clause in the school appropriations bill that required teachers to sign a statement each payday declaring that they had not taught or advocated communism.

"No American is in favor of 'advocating' communism, but to 'teach' it in the sense of explaining to students what communism is should be a part of any educational program," she wrote in an article for the Radcliffe Quarterly that was excerpted in The Post. "Fear ruled the teachers in the history classes and, of course, many of them skipped over any mention of communism. In effect, the Congress of the United States was writing a history course for the pupils of Washington."

In 1937, Congress repealed the clause.

Mrs. Doyle was born in Cambridge, Mass. She graduated from Radcliffe College and then taught in the Cambridge schools. In an interview with The Post in 1968, when she had returned to Radcliffe for a reunion, she recalled marching in a suffrage parade in Boston. That was in 1915, and to take part in the parade she passed up a chance to attend a Harvard-Brown football game with a young Harvard instructor named Henry Grattan Doyle.

"Principle prevailed," she said. "But I am a woman of determination and, in those days, fleet of foot, and I chased that young man until I caught him, and he was my husband for 47 years."

The Doyles moved to Washington in 1917. Dr. Doyle taught at George Washington University and became dean of its Columbian College. He died in 1964.

Mrs. Doyle became active in the League of Women Voters and was president of the Washington chapter in the late 1920s. She also held national office in the organization. During World War II, she was president of the D.C. Commisioners' War Hospitality Committee. In the 1950s, she chaired the Advisory Commission to the D.C. Juvenile Court.

Her numerous honors included the National Brotherhood Award of the National Conference of Christians and Jews in 1956. Radcliffe designated her a distinguished alumna and in 1984, on the 60th anniversary of her own graduation, she led the commencement procession at Harvard University.

Survivors include a son, Robert Carr Doyle of Chevy Chase; a daughter, Marion Wade Campbell of Richmond; eight grandchildren, and three great-grandchildren.