This was the second weekend of demonstrations, with more than 1 million people coming out last weekend for the Women's March
Olivia Katbi Smith told CNN affiliate KATU
she showed up Saturday at Portand International Airport because she believes Trump's immigration policies are cruel.
"I think it's horrific and terrible and we are basically condemning people to death by not allowing them to come here," she said.
She said the event appeared to be impromptu. She heard about it on Twitter and thinks most people did the same.
In New York City, a large crowd massed at John F. Kennedy International Airport to protest the detention of two Iraqis
who were later released.
"Mr. President, look at us," said US Rep. Nydia Velazquez, a New York Democrat. "This is America. What you have done is shameful. It's un-American."
The protesters gathered in Terminal 4 at JFK and carried signs reading, "We are all immigrants!" and "No ban! No wall!"
Several New York officials showed support for the protests.
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.
New York Mayor Bill de Blasio tweeted: "What's happening at JFK is shameful. @NYCImmigrants Affairs Commissioner Nisha Agarwal is on the ground now working to help."
One of the detained men, Hameed Khalid Darweesh, was released early Saturday afternoon. He worked with the US government for 10 years after the United States invaded Iraq.
The other detained man, Haider Sameer Abdulkaleq Alshawi, had been granted a visa to join his wife, who worked for a US contractor in Iraq, and son, both of whom already live in the United States as refugees. Alshawi was released later Saturday.
Rep. Jerrold Nadler, another Democrat from New York, said 10 other travelers were detained, but their status was unclear Saturday night.
Virginia Gov. Terry McAuliffe joined protesters at Dulles International Airport outside Washington.
"This executive order is antithetical to the values that make America great, and it will make our country less safe," he said in a statement.
In Portland, one demonstrator carried a sign that said, "Portland coffee comes from Yemen," one of the seven Muslim-majority nations on the no-travel list.
Lucia Martinez told KATU she used to be a "hashtag activist" but felt compelled to protest at the airport.
"This was the last straw," she said of Trump's policies. "We're all immigrants."
A group of community activists, attorneys and others gathered at O'Hare International Airport in Chicago.
Protests also took place at airports in Newark, New Jersey; Boston; San Francisco; Denver, Colorado; and Dallas.
Protests are scheduled Sunday in Orlando, Boston, Philadelphia, Atlanta, Seattle, Washington and Chicago, mostly at airports.