The organization was founded in October 2002 during the build-up to the United States' 2003 invasion of Iraq by dozens of groups including the National Organization for Women, National Council of Churches, Peace Action, the American Friends Service Committee, Black Voices for Peace, Not In Our Name, September Eleventh Families for Peaceful Tomorrows, and Veterans for Peace. Its first joint action was anti-war protests on International Human Rights Day, December 10, 2002.[3] The direct precursor to UFPJ was "United We March!", initiated by Global Exchange, the Green Party of the United States, and others, which organized the April 20, 2002 demonstration against the U.S. invasion of Afghanistan.