William N. Richards, 77, who was a museum administrator at the Smithsonian Institution from 1976 to 1986, died of congestive heart failure Sept. 13 at Holy Spirit Hospital in Camp Hill, Pa. During his decade in Washington, he lived in Vienna.

After leadership posts at museums and state offices in his native Pennsylvania, Mr. Richards became assistant to the assistant secretary for museum programs at the Smithsonian. From 1984 until his retirement, he was the acting assistant secretary in that division.

Mr. Richards had served on the board for accreditation of the American Association of Museums and remained a member of the organization until his death.

Born in Lansford, Pa., Mr. Richards interrupted his undergraduate education at Muhlenberg College to enter the Army Air Forces during World War II. Returning from Europe in 1945, he finished his history degree at Muhlenberg and also received a master's degree in history from the University of Pennsylvania in 1949.

After a decade as a historian with the Pennsylvania Historical and Museum Commission, Mr. Richards was director of the state bureau of museums until moving to Washington.

His hobbies included photography, and he was a member of Camp Hill Baptist Church in Pennsylvania.

He is survived by his wife of 47 years, Virginia Werner Richards of Camp Hill; a daughter; a granddaughter; and a brother.