Dr. Rayford W. Logan, 85, a writer and historian who was chairman of the history department at Howard University for more than 20 years before being named professor emeritus of history in 1965, died of congestive heart failure Nov. 4 at Howard University Hospital. He lived in Washington.

Dr. Logan was an educator for 40 years, serving on the faculty of Virginia Union University, and chairing the history department at Atlanta University, before joining Howard in 1938. He was chairman of Howard's history department from 1942 until retiring in 1964.

He contributed book reviews to The Washington Post on topics that included African, Latin-American and United States history, and the socio-economic problems of blacks.

His own works included "The Diplomatic Relations of the United States with Haiti, 1776 to 1891," and "The Negro In American Life And Thought: The Nadir, 1877 to 1901."He also was the author of a history of Howard University, and biographical works on black leaders Frederick Douglass and W.E.B. Du Bois. At the time of his death, he was working on "The Dictionary of American Negro Biography," and a series of essays, "The International Struggle for Human Rights."

In addition to a life of writing and teaching, Dr. Logan served with a number of political and civic organizations. He was secretary of Pan-African congresses, during the 1920s, which met in Paris, London, Lisbon, and New York. It was during this time that he worked with W.E.B. Du Bois.

Dr. Logan served in the State Department's Inter-American Affairs bureau in the early 1940s, and from 1940 to 1945 chaired the federal committee on participation of blacks in national defense. He also was a member of the U.S. national commission for UNESCO from 1947 to 1950.

He was a 1980 recipient of the NAACP's Spingarn Medal, and was awarded honorary doctorates by Williams College and Howard University. In 1971, Howard named him Distinguished Professor of History.

Dr. Logan was a native of Washington and graduate of the old M Street High School. He was a 1917 graduate of Williams College where he was a member of Phi Beta Kappa, and earned master's degrees there and at Harvard University. He earned a doctorate in history at Harvard in 1936.

He was a first lieutenant in France during World War I, one of the few black commissioned officers in the Army at that time.

His wife, the former Ruth Robinson, died in 1966.

Dr. Logan leaves no immediate survivors.