Reply #21: It was Eisenhower, 1957:

[WinkyDink]

U.S. Congressman Brooks Hays and Little Rock Mayor Woodrow Mann asked the federal government for help, first in the form of U.S. marshals. Finally, on September 24, Mann sent a telegram to President Eisenhower requesting troops. They were dispatched that day and the President also federalized the entire Arkansas National Guard, taking it away from the Governor.

On September 25, 1957, the nine black students entered the school under the protection of 1,000 members of the 101st Airborne Division of the United States Army.
http://www.centralhigh57.org/