Chapman, Oscar L. (Oscar Littleton), 1896-1978

Secretary of the Interior Oscar Chapman (standing) speaks to the Bureau of Reclamation's Operations and Maintenance Regional Supervisors during a conference at the Department of the Interior. Also pictured: Senator Joseph C. O'Mahoney (seated, right of Chapman). All others unidentified.

Attendees of the Bureau of Reclamation's Operation and Maintenance Regional Supervisors' Conference pose for a picture on the steps of the Interior building. Pictured, front row: Assistant Secretary of the Interior William Warne (second from left); Secretary of the Interior Oscar Chapman (center); and Bureau of Reclamation Commissioner Michael Straus (second from right). All others unidentified.

An unidentified man speaks to the Bureau of Reclamation's Operation and Maintenance Regional Supervisors during a conference at the Department of the Interior. Also pictured: Secretary of the Interior Oscar Chapman (along back wall, left); and Senator Joseph C. O'Mahoney (along back wall, right). All others unidentified.

Secretary of the Interior Oscar Chapman (center) with unidentified men from the Bureau of Reclamation's Operation and Maintenance Regional Supervisors' Conference at the Department of the Interior.

Secretary of the Interior Oscar Chapman (standing) speaks to the Bureau of Reclamation's Operations and Maintenance Regional Supervisors during a conference at the Department of the Interior. Also pictured: Bureau of Reclamation Commissioner Michael Straus (left, against wall); and Senator Joseph C. O'Mahoney (seated, right of Chapman). All others unidentified.

Members of the Cabinet greet President Harry S. Truman at Washington National Airport upon his return from a vacation in Key West, Florida. Pictured, foreground, left to right: President Truman; Secretary of the Interior Oscar Chapman; and Secretary of Defense Louis Johnson. All others are unidentified.

From left to right: unidentified; Under Secretary of the Interior Oscar Chapman; Arthur Demaray, Associate Director, National Park Service; Arthur Goldschmidt, Special Assistant to the Secretary; and Robert Day, Assistant to the Secretary at a reception for the members of the U.N. World Conservation Conference.

From left to right: Under Secretary of the Interior Oscar Chapman, former First Lady Eleanor Roosevelt, and Ann (Mrs. Oscar) Chapman at a Memorial Day service in Hyde Park, New York.

Under Secretary of the Interior Oscar Chapman (right) and Ann (Mrs. Oscar) Chapman visit the grave of President Franklin D. Roosevelt on the grounds of his home in Hyde Park, New York.

Under Secretary of the Interior Oscar Chapman (left) and Mrs. Eleanor Roosevelt at the Memorial Day service at the home of former President Franklin D. Roosevelt in Hyde Park, New York.