Early color telecasts could be preserved only on the black-and-white kinescope process introduced in 1947. It was not until September 1956 that NBC began using color film to time-delay and preserve some of its live color telecasts. Ampex introduced a color videotape recorder in 1958, which NBC used to tape "An Evening With Fred Astaire", the oldest surviving network color videotape. This system was also used to unveil a demonstration of color television for the press. On May 22, 1958, President Dwight D. Eisenhower visited the WRC-TV NBC studios in Washington, D.C., and gave a speech touting the new technology's merits. His speech was recorded in color, and a copy of this videotape was given to the Library of Congress for posterity.