How Columbia University became the driving force behind protests over the war in Gaza

As the two-week standoff between pro-Palestinian protesters and college administrators at Columbia University in New York came to a head on Tuesday, officials anxiously monitored whether the fallout would spark more protests on college campuses around the country or quell what has been a growing movement.

Protesters at Columbia dug in, taking over an academic building that has a history of being occupied by student protesters going back nearly 60 years to the Civil Rights Movement and the Vietnam War. The escalation came after the passing of a Monday deadline issued by the university's administration for protesters to leave an encampment.

A timeline illustrating how Columbia University became the driving force behind protests on college campuses across the country:

Students set up an encampment at Columbia University the same day university president Nemat Shafik is called for questioning before Congress. Shafik is heavily criticized by Republicans who accuse her of not doing enough to combat concerns about antisemitism on Columbia's campus. Allegations of antisemitism arose during pro-Palestinian protests against Israel's actions in the war in Gaza.

» READ MORE: Penn says it will pursue disciplinary action against encamped pro-Palestinian protesters

The public grilling session comes four months after a similarly contentious congressional hearing led to the resignations of two Ivy League presidents. Unlike her counterparts, who focused their responses on protecting free speech, Shafik strongly denounced antisemitism, saying it “has no place on our campus.”

New York City police are called to Columbia's campus to disband the protest encampment and arrest more than 100 protesters. Those detained include the daughter of Democratic U.S. Rep. Ilhan Omar, who a day earlier had questioned Shafik about the school's treatment of pro-Palestinian protesters.

The arrests, which New York Mayor Eric Adams says were requested by Columbia officials, garner national attention and inflame college protests nationwide. A day later, the University of Southern California announces that it has canceled the keynote commencement speech by filmmaker Jon M. Chu. USC had already disallowed its student valedictorian, who is Muslim, from speaking at the May 10 commencement.

In the coming days, pro-Palestinian encampments will be set up at the University of Michigan, the Massachusetts Institute of Technology and the University of North Carolina.

Columbia cancels in-person classes, and an encampment at New York University swells to hundreds of protesters. NYU officials call in police after warning the crowd to leave and says the scene has become disorderly. Police arrest dozens of protesters at NYU and at Yale University in New Haven, Connecticut. The gates to Harvard Yard in Cambridge, Massachusetts, are closed to the public.

» READ MORE: Student protests over Gaza war are forcing Penn and other U.S. universities to face ‘impossible’ demands

President Joe Biden addresses the unrest and seeks to find a narrow middle ground by condemning "antisemitic protests," adding that he also condemns "those who don't understand what's going on with the Palestinians."

Columbia administrators set a new midnight deadline for protesters to clear the encampment. While some leave, others dig in and refuse to disband until the school agrees to stop doing business with Israel or any companies that support the latest Israel-Hamas war.

Elsewhere, police make more arrests on other university campuses. At the University of Texas at Austin, hundreds of local and state police — including some on horseback and holding batons — aggressively clash with protesters, pushing them off campus grounds, and arresting more than 30 people. At the University of Southern California, police peacefully arrest student protesters.

Columbia University students say they're at an impasse after exhaustive negotiations with administrators and they intend to continue their encampment until their divestment demands are met. That comes after hundreds of protesters have been arrested nationwide over the previous nine days. The school sends students an email saying that bringing back police "at this time" would be counterproductive.

Meanwhile, schools across the country where protests have taken root prepare to shut down encampments over reports of antisemitic activity and concerns the protests will mar upcoming commencement ceremonies.

Columbia makes good on its promise to suspend students who defy a 2 p.m. deadline to leave the encampment of more than 100 tents. Instead of vacating, hundreds of protesters remain, marching around the quad and weaving around piles of temporary flooring and green carpeting meant for graduation ceremonies that are scheduled to begin next week.

Around the country, the number of arrests at campuses nationwide approaches 1,000 as the final days of class wrap up.

Dozens of protesters take over Hamilton Hall on Columbia's campus, barricading entrances and hanging a "Free Palestine" banner from a window as administrators warn that they face expulsion for doing so. Protesters insist they will remain at the hall until the university agrees to three demands: divestment from Israel and companies supporting the war in Gaza, financial transparency and amnesty for protesters.

Hours later, New York City police carrying riot shields storm the building and clear dozens of people from it, sweeping the encampment on the campus as well. The action from city police came at the request of the university, according to a police statement.

Hours after the clash between protesters and police on the Columbia campus, dueling groups of protesters spar at the University of California, Los Angeles, grappling in fistfights and shoving, kicking and using sticks to beat one another. Police wearing helmets and face shields form a line to slowly separate the groups of pro-Palestinian and pro-Israeli demonstrators and quell the violence.