Protestors at anti-Trump protest in Los Angeles
Demonstrators are seen during a national day of action called "Keep Families Together" to protest the Trump administration's "Zero Tolerance" policy in Los Angeles, California, U.S. June 30, 2018.REUTERS/Monica Almeida

Thousands of people in hundreds of cities across the United States came together on Saturday to raise their voice against the disheartening administration of the US government under President Donald Trump.

Thousands of Americans from all walks of life took to the streets of cities across the US and chanted "families belong together", nearly two months after President Donald Trump implemented the "zero tolerance" policy toward undocumented immigrants, prompting the separation of thousands of children from their parents.

Anti-Trump protest in Los Angeles
Demonstrators protest during a national day of action called "Keep Families Together" to protest the Trump administration's "Zero Tolerance" policy in Los Angeles, California, U.S. June 30, 2018.REUTERS/Monica Almeida

The main rally on Saturday was in Washington, D.C., but hundreds of marches, protests and rallies took place across the country in major cities like New York, Philadelphia, Chicago, Milwaukee, Denver, Miami, St. Louis, San Francisco and Los Angeles, where crowds called for the immediate reunification of migrant families and an end to family detentions and separations, reports CNN.

According to organisers, the protesters called for three demands: they want separated migrant families to be reunited immediately; they want the government to end family detentions, and they want the Trump administration to end its Zero Tolerance Policy.

Deonstrator hold up a placard at the anti-Trump protest in Los Angeles
A demonstrator holds up a placard during a national day of action called "Keep Families Together" against the Trump administration's 'Zero Tolerance' policy in Los Angeles, California, U.S. June 30, 2018.REUTERS/Monica Almeida

Attendees in Washington marched from Lafayette Square to the White House -- though the President is at his golf resort in New Jersey -- and down Pennsylvania Avenue, past the Trump Hotel, where chants of "Shame! Shame! Shame!" broke out.

In Atlanta, demonstrators carried cages with dolls inside, and marchers in Chicago encouraged each other to "fight back".

In New York, protesters overflowed Foley Square in Lower Manhattan and filled the surrounding sidewalks. Crowds also inched across the Brooklyn Bridge for more than two hours.

Anti-Trump protestors at Brooklyn Bridge in New York
Demonstrators cross the Brooklyn Bridge during "Keep Families Together" march to protest Trump administration's immigration policy in New York, U.S., June 30, 2018.REUTERS/Shannon Stapleton

Protesters in Houston chanted, "No baby jails", outside City Hall. Crowds gathered in McAllen, Texas, the border town where one of the Customs and Border Protection agency's processing detention centres sits.

Several celebrities joined the rallies, including singer-songwriter John Legend, who sang his song "Preach" at a demonstration in Los Angeles, veteran singer Cher who encouraged people to vote in November, actresses Kerry Washington and Amy Schumer marched in New York while singer Alicia Keys performed in Washington.

John Legend performs 'Preach' at the anti-Trump protest in Los Angeles, California.
John Legend performs during a national day of action called "Keep Families Together" to protest the Trump administration's 'Zero Tolerance' policy in Los Angeles, California, U.S. June 30, 2018.REUTERS/Monica Almeida

Many attendees carried signs, some demanding a change to the administration's policy, others celebrating the contributions that immigrants make to the country.

There were also plenty of signs and shirts declaring, "I really do care, do u?" -- a dig at the jacket First Lady Melania Trump wore while departing for a trip to the southwest border last week.

Event organisers said Saturday's protests were about addressing an ethical issue.

"This is not left or right," Anna Galland, Executive Director of MoveOn.org, one of the organisations leading Saturday's protests, told CNN.

Galland said she and Indian American Congresswoman Pramila Jayapal put out a call for protests less than two weeks ago and they were "overwhelmed" by the response.

Pramila Jayapal at anti-Trump protest in Washington DC
U.S. Representative Pramila Jayapal (D-WA) (C) walks to be arrested as she joined demonstrators calling for "an end to family detention" and in opposition to the immigration policies of the Trump administration, at the Hart Senate Office Building on Capitol Hill in Washington, U.S. June 28, 2018.REUTERS/Jonathan Ernst

This is beyond politics... You don't put kids in cages. You don't separate breastfeeding babies from their mothers. You don't put asylum-seekers in prison, and we're calling for an end to that today," said Jayapal, who was recently arrested during a similar protest at the Senate office building on June 28.

More than 2,500 undocumented children were separated from their parents in the weeks since the zero-tolerance policy took effect, reports CNN.

Under the policy, any adult caught crossing the border illegally faced prosecution and their children were sent to federal shelters all over the US.

California Lt governor Gavin Newsom at anti-trump protest
California Lieutenant Governor Gavin Newsom and his family attend a national day of action called "Keep Families Together" to protest the Trump administration's "Zero Tolerance" policy in Los Angeles, California, U.S. June 30, 2018.REUTERS/Monica Almeida

There were widespread outrage over the separations which prompted Trump to sign an executive order on June 20 reversing the family separation policy.

Six days after that order was signed, only six children had been reunited with their parents -- meaning more than 2,000 children were still in limbo.