Two British Fathers 4 Justice activists have been arrested at gunpoint by a Swat team at the Lincoln Memorial in Washington DC.
Jolly Stanesby and Mike Downes scaled the statue as the tourists gathered around were warned to put their cameras down and stop “encouraging them”.
A “support crew” of four other campaigners was also held as the memorial was evacuated by US authorities.
The men, who wore Captain America and Batman costumes, were being held in custody in Washington and could be deported or put on trial.
The group – which campaigns to ensure divorced fathers are given access to their children – warned that this was the first of “many, many more” similar protests across the States.
Matt O’Connor, founder of Fathers 4 Justice, said: “Yet again Fathers 4 Justice in the UK has led the way with an audacious protest to raise the global profile of fatherlessness and the social catastrophe it is causing in first world countries.
“Given the problem is not one that is unique to any one country or culture, a first world problem requires a first world, international response.
“This is our response to the inaction of the US authorities. There will be many, many more to follow.
“Now we have lit the flame, we can begin the struggle to make equal parenting a reality in the United States, and combat the insidious gender apartheid that separates children from their fathers in the family courts.”
The group plans to run its first national awareness campaign in the US during the presidential elections.
Stanesby and Downes unveiled their Captain America and Batman costumes after first scaling the memorial dressed as tourists and unfurled a white banner which read: “For the Fathers of the Nation: Fathers 4 Justice has arrived www.f4jusa.com.”
The memorial, which is on the National Mall in the US capital, was built to honour the 16th US President Abraham Lincoln and has been the site of many famous speeches, including Martin Luther King’s “I Have a Dream”, delivered on August 28 1963, during the rally at the end of the March on Washington for Jobs and Freedom.
Fathers 4 Justice has staged similar stunts in the UK including scaling Big Ben, York Minster, Westminster Abbey and the Royal Courts of Justice, as well as throwing purple powder at then Prime Minister Tony Blair in the House of Commons.