Stevenson was also the first woman to be appointed to the board of directors of the National Gallery of Art in Washington, D.C., and the first woman to become the chairman of that board. Along with local art enthusiasts Owen Day and Sam Cantey III, Stephenson assembled "An Art Exhibition for the President and Mrs. John F. Kennedy" which decorated the suite in the Hotel Texas in Fort Worth, Texas, occupied by United States President John F. Kennedy and Jacqueline Kennedy on the night before his assassination on November 22, 1963.