Columbia University's Hamilton Hall, occupied by protesters early Tuesday morning, has been occupied numerous times by student activists over the past half-century.
Here are some of the notable moments of student protests at this building.
1968
The building, which opened in 1907, was first opened in April 1968 by hundreds of students during protests against the Vietnam War, racism, and the Columbia Plan to build a gymnasium in nearby Morningside Park. It was an occupied building. Students barricaded themselves inside and prevented the acting dean, Henry S. Coleman, from leaving his office overnight.
Protesters used furniture to keep Coleman inside, and protesters from an African American student group asked white students in the building to leave. This sparked another round of protests against black students as white students continued to demonstrate in other buildings on campus.
A week later, police entered the building through an underground tunnel and removed the students. Police stomped protesters, beat them with batons and dragged some down concrete steps. More than 700 people were arrested.
During another protest in May 1968, approximately 250 student protesters occupied Hamilton Hall again. After about 10 hours, police removed them from the building.
1972
During anti-war protests in 1972, students also locked themselves in Hamilton Hall, named after Alexander Hamilton, the first US Secretary of the Treasury. Protesters removed furniture from classrooms and offices and used it as barricades. They also locked the door with a chain after management told them to leave.
About a week later, police re-entered the building through the underground passage and removed the protesters. There were no injuries or arrests. However, the university announced that the students would be charged with criminal trespass and contempt of a court injunction prohibiting them from occupying Columbia University buildings.
1985
In 1985, demonstrators occupied Hamilton Hall, demanding that the university divest from companies doing business in South Africa. Universities were reluctant to comply.
Three weeks later, the students ended their occupation just before a judge ordered Hamilton Hall to reopen. Although there was no guarantee that the policy would change, students saw the protests as a moral victory. Later that year, Columbia University's Board of Trustees voted to sell all of the university's holdings in American companies operating in South Africa.
1992
In 1992, students occupied Hamilton Hall in protest of the Columbia government's plan to turn the Audubon Theater and Ballroom, where Malcolm X was assassinated in 1965, into a biomedical research complex. The blockade lasted less than a day.