The affected airports included Los Angeles, San Francisco, Washington, Dallas, New York's JFK, Raleigh, Houston, Seattle, Portland, Atlanta and more.
Crowds gathered in and around terminals to challenge the executive order, which temporarily bars entry to the United States from seven Muslim-majority countries. It also bans all refugee admissions for the next 120 days.
Like they had a week ago at the Women's March rallies across the country, demonstrators carried thousands of colorful handmade signs, many written with markers on cardboard panels.
Throngs of people protested at major US landmarks, including the White House, Boston's Copley Square and Battery Park in Manhattan.
The park was packed with more than 10,000 people, according to an official at City Hall. New Jersey Sen. Cory Booker, New York City Mayor Bill de Blasio, Rep. Nydia Velazquez, New York Sens. Chuck Schumer, the Democratic minority leader, and Kirsten Gillibrand took turns speaking.
Protesters sang and chanted: "No hate, no fear, immigrants are welcome here." At airports, the crowds waved signs in solidarity with travelers stuck inside -- students, doctors, professors and refugees. They cheered as impacted travelers left airports and reunited with loved ones. But many more remain in limbo.
By Sunday night, everyone who had been detained in the initial halt of Friday's executive order had either been released into the United States or put on a plane out of the country, Department of Homeland Security spokeswoman Gillian Christensen told CNN. She added that 392 green card holders, or lawful permanent residents, were given exemptions and entered the country.
But opponents of the travel ban say the fight is just beginning.
Even though judges from New York to Seattle granted limited relief for citizens of the seven countries who had already arrived in the US with a valid visa or green card, advocacy groups said they plan to file additional lawsuits in days to challenge the constitutionality of the order.
Airports make room
Crowds began gathering at Terminal 4 at John F. Kennedy International Airport on Saturday to protest the detention of two Iraqis
who were later released. Protests later sprung up at other airports where people were blocked trying to enter the country.
Airport officials for the most part accommodated the protests, temporarily closing security checkpoints and diverting traffic to make room for demonstrators.
Gov. Andrew Cuomo ordered the Port Authority of New York and New Jersey to reverse an earlier decision to restrict passage aboard the JFK Airport AirTrain to ticketed passengers and airport employees only.
He also instructed state police and the Metropolitan Transportation Authority to assist with security and transportation for protesters.
"The people of New York will have their voices heard," Cuomo said.
San Francisco International Airport temporarily closed the international terminal security checkpoint and sent passengers to another boarding area to let protests go forward.
At the Philadelphia airport, police closed lanes of traffic to vehicles to make room for demonstrators singing the classic Woody Guthrie protest song, "This Land Is Your Land."
At Chicago O'Hare Airport, immigration lawyers set up with their laptops, forming a makeshift legal clinic to help travelers arriving from the banned countries.
At Raleigh-Durham Airport, officials ended the protest due to safety concerns. Organizers had a permit for 150 people and close to 2,00 showed up, airport spokeswoman Kristie VanAuken said.
"It was a peaceful protest and there were no arrests, but we shut it down early for the safety of everyone involved," VanAuken said.
While the protest at Portland International Airport remained largely peaceful, at times Trump supporters and protesters clashed, forcing airport police to move in. A Port of Portland and airport spokesperson told CNN affiliate KOIN 6 News
that one person was assaulted during the protest and "removed for medical care."
Families heartened by support at airport
A federal judge in New York granted an emergency stay Saturday night for citizens of the seven Muslim-majority countries who had already arrived in the US or were in transit and hold valid visas, ruling they cannot be removed from the United States.
The move paved the way for reunions at the airports, as well as heartache.
Two Syrian friends, Muhamad Alhaj Moustafa and Said Hajouli who came to the US to train as doctors waited at the Washington Dulles International Airport, worried whether they'd see their wives again.
Hajouli's wife was released Sunday. But Moustafa's wife, who has lived in the US for almost a year and holds a J2 visa, the kind given to spouses of immigrants, was put on a plane back to Qatar on Saturday.
Moustafa doesn't know what to do to help his wife.
"I was hopeless, but seeing this," he said as he pointed to the crowds of people holding welcome signs, "this gives me hope."