When the White House underwent a major renovation from 1948 to 1952, President Harry S. Truman moved into Blair House and chose this room as his office. In President Truman’s time, the walls were painted green; he worked at a small desk with his back to the fireplace.
An unsuccessful attempt was made on President Truman's life on November 1, 1950, while he was living at Blair House. White House Police Officer Private Leslie Coffelt, who was guarding the Lee House door closest to the President’s office, died while repelling the attackers, two Puerto Rican Nationalists. He remains the only White House police officer ever killed in the line of duty. A memorial plaque commemorating Officer Coffelt is affixed to Blair House’s front fence.
Before President Ronald Wilson Reagan’s state funeral on June 11, 2004, former First Lady Nancy Reagan received visitors in the Truman Study.