Sanders later described his time in Chicago as "the major period of intellectual ferment in my life". While there, he joined the Young People's Socialist League (the youth affiliate of the Socialist Party of America) and was active in the Civil Rights Movement as a student for the Congress of Racial Equality (CORE) and the Student Nonviolent Coordinating Committee (SNCC). Under Sanders's chairmanship the university chapter of CORE merged with the university chapter of SNCC. In January 1962 Sanders went to a rally at the University of Chicago administration building to protest university president George Wells Beadle's segregated campus housing policy. "We feel it is an intolerable situation when Negro and white students of the university cannot live together in university-owned apartments," Sanders said at the protest. Sanders and 32 other students then entered the building and camped outside the president's office. After weeks of sit-ins Beadle and the university formed a commission to investigate discrimination. Following further protests, the University of Chicago ended official racial segregation in private university housing in the summer of 1963. Joan Mahoney, a member of the University of Chicago CORE chapter at the time and a fellow participant in the sit-ins, described Sanders in a 2016 interview as "a swell guy, a nice Jewish boy from Brooklyn, but he wasn't terribly charismatic. One of his strengths, though, was his ability to work with a wide group of people, even those he didn't agree with". Sanders once spent a day putting up fliers protesting against police brutality, only to eventually notice that a Chicago police car was shadowing him and taking them all down.