Governor Orval Eugene Faubus (Democrat) of Arkansas used the Arkansas National Guard to prevent school integration at Little Rock Central High School in 1957. President Eisenhower (Republican) nationalized state forces and sent in the US Army to enforce federal court orders. Governors Ross Barnett of Mississippi and George Wallace of Alabama physically blocked school doorways at their respective states' universities. Birmingham's public safety commissioner Eugene T. "Bull" Connor advocated violence against freedom riders and ordered fire hoses and police dogs turned on demonstrators during the 1963 Birmingham Children's Crusade. Sheriff Jim Clark of Dallas County, Alabama, loosed his deputies during the 1965 "Bloody Sunday" event of the Selma to Montgomery march, injuring many of the marchers and personally menacing other protesters. Police all across the South arrested civil rights activists on trumped-up charges.