Mark Rudd began his years at Columbia College in the fall of 1965. His political activism flourished in his second year as the Vietnam War galvanized vigorous opposition among college youth. Rudd devoted his time to anti-war activities and became involved with Students for a Democratic Society, or SDS, becoming the chair of the Columbia chapter of the left-leaning political group. He became convinced that drastic action and not passive resistance was needed to alter social injustices.
One of the foremost institutions of higher learning, Columbia University was part of the decision-making apparatus in shaping American policy in South East Asia, Rudd asserted. In a position paper for SDS, he wrote it was necessary "to end university complicity with the war: I.D.A. (Institute for Defense Analyses), N.R.O.T.C., C.I.A. contracts, recruiting, etc."
Rudd believed that the students and faculty needed to be "radicalized." In 1968, a pivotal year of Columbia's history, Rudd became bolder and more vocal in the campus community. He along with the members of SDS engaged in spontaneous demonstrations that were targeted at Columbia's complicity in the war effort in Vietnam.
Carrying posters and chanting slogans, on March 27, 1968, a month before Columbia buildings at the Morningside Heights campus were taken over, Rudd led about 110 students into Low Library at noon to protest against both the ban on indoor demonstrations and the University's cooperation with the Institute of Defense Analyses.
Many SDS rallies took place on the sundial. During an demonstration on April 23, 1968, Rudd advanced the position that the university was run by a small ruling group with connections in business, the military, and the government, that runs America and oppresses the people, especially the poor and African-American. Through IDA and other agencies, Columbia was aiding the forces of American imperialism in South East Asia.