Hamilton Hall, the building at Columbia University that protesters occupied early Tuesday morning, has been occupied several times by student activists over the past half-century.
Here are some of the notable moments of student protest at the building.
1968
The building, which opened in 1907, was the first that hundreds of students seized in April 1968 during protests over the Vietnam War, racism and Columbia’s plans to build a gymnasium in nearby Morningside Park. Students barricaded themselves inside, preventing the acting dean, Henry S. Coleman, from leaving his office for one night.
As demonstrators used furniture to keep Mr. Coleman inside, protesters who were part of an African American student group asked white students in the building to leave. That created a separate protest for Black students, as the white students went on to demonstrate in other buildings on campus.
A week later, the police entered the building through underground tunnels and cleared the students. Police officers trampled protesters, hit them with nightsticks and dragged some down concrete steps. More than 700 people were arrested.
During another round of protests in May 1968, about 250 student protesters occupied Hamilton Hall again. The police removed them from the building about 10 hours later.
1972
Students also locked themselves in Hamilton Hall, which was named after Alexander Hamilton, the first treasury secretary of the United States, during antiwar protests in 1972. Protesters took furniture from classrooms and offices to use as barricades. They also locked doors with chains as administrators told them to leave.
The police cleared the building of protesters after about a week, again by entering through an underground passage. No one was injured or arrested. But the university said that the students would be prosecuted for criminal trespass and contempt of a court injunction that had forbidden the occupation of Columbia buildings.
1985
In 1985, protesters occupied Hamilton Hall as they demanded that the university divest from companies that were doing business in South Africa. The university was reluctant to comply.
Three weeks later, the students ended their occupation just before a judge ordered them to reopen Hamilton Hall. While there were no guarantees of any change in policy, the students viewed the protest as a moral victory. Later that year, Columbia’s board of trustees voted to sell all of the university’s stock in American companies doing business in South Africa.
1992
In 1992, students occupied Hamilton Hall in protest of Columbia’s plans to turn the Audubon Theater and Ballroom, where Malcolm X had been assassinated in 1965, into a biomedical research complex. The blockade lasted less than a day.