A sit-in at a Swarthmore College fraternity entered its fourth day Tuesday as student protesters demand the banning of two Greek organizations after offensive material from one fraternity’s “meeting minutes” surfaced in April.

The action started Saturday afternoon, and organizers say they don’t plan to leave until their demands are met. Based on the results of past sit-ins at the school, that’s not a bad bet.

The “sit-in” — a direct action protest style in which participants sit down and occupy a space to draw attention to their grievances — has been the dissent method of choice at the Quaker college with a tradition of consensus decisions since at least the late 1960s. Nonviolent sit-ins in America were created by civil rights activists and popularized in 1960 when black students in Greensboro, N.C., protested by sitting at a segregated lunch counter, setting off a wave of anti-segregation sit-ins across the South.

At Swarthmore, a most selective liberal arts school in Delaware County that enrolls about 1,600 students, sit-ins have long been a rite of passage and have gotten results, whether they were protesting low black enrollment at the school or the impending death of the football program. Here’s a look at how they’ve been used there over the years:

January 1969

How long the sit-in lasted: A week.

What they wanted: Higher black student enrollment and black administrators.

How it went down: About 40 black students staged a sit-in at the school’s admissions office, demanding the school admit more black students, which was predominantly white at the time, according to Inquirer archives. The protest ended abruptly Jan. 16, 1969, when the college president died of a heart attack. The day before his death, the president had convened a group of faculty to review the demands and issue recommendations.

March 1970

How long the sit-in lasted: A weekend.

What they wanted: Control of a forthcoming black cultural center on campus.

How it went down: The school’s Afro-American Society staged a sit-in around the desk of the college president, demanding he give students the right to control policy and programming at the school’s to-come black cultural center. The sit-in ended after the president created a steering committee made up of both students and faculty.

December 1985

How long the sit-in lasted: Nine days.

What they wanted: Increased black enrollment and divestment from firms doing business in South Africa.

How it went down: About 50 students, both black and white, camped out at the school president’s office. The sit-in ended when the school proposed appointing a black student aide to the school’s admissions office and taking the divestment issue before the faculty.

April 1994

How long the sit-in lasted: A day.

What they wanted: New programs to deter hate speech.

How it went down: A couple of dozen students staged a quiet sit-in at the administration building after at least two instances of offensive graffiti targeting minority and LGBTQ students cropped up on campus. The school president condemned the acts and referred to the sit-in as “sensitive and meaningful,” according to Inquirer archives. It’s unclear if their demands for new programs were met.

December 2000

How long the sit-in lasted: A day.

What they wanted: The reinstatement of three sports programs the school announced it would eliminate.

How it went down: About 100 students protested a decision made by administrators to cut the football, wrestling, and women’s badminton programs. But this time, the sit-in at Parrish Hall didn’t work. The college reaffirmed its decision in early January 2001 (not to mention that the “sit-in” was more of a “stand-in”).

April 2015

How long the sit-in lasted: 32 days.

What they wanted: The school to divest fossil fuels from its endowment portfolio.

How it went down: In what activists said was the longest sit-in Swarthmore had seen, about 175 students slept for a month in the school’s Parrish Hall. The chair of the college’s Board of Managers said the school would increase sustainable practices, but wouldn’t commit to divestment. Months later, the school approved a $300,000 investment to improve energy conservation on campus.

May 2018

How long the sit-in lasted: Nine days.

What they wanted: New sexual-assault reporting policies, a fraternity ban, and the resignation of a dean.

How it went down: Organizing for Survivors, a campus advocacy group, put together a nine-day sit-in at the school’s administration offices and accused officials of mishandling sexual-assault investigations under Title IX. The sit-in ended after the group had a formal meeting with the college president. A week later, the dean who was the focus of their protest announced her resignation.

April 2019

How long the sit-in lasted: Four days ... so far.

What they want: The banning of two fraternities -- Phi Psi and Delta Upsilon -- from operating on campus and the termination of the fraternity’s leases.

How it has gone down: Activists say about 100 students are occupying the Phi Psi fraternity and sleeping both inside and outside the fraternity house. The college president said in a message to the Swarthmore community that a task force convened to review Greek life will present recommendations to her by Friday.