Cindy Sheehan, sometimes called "Peace Mom," has been perhaps the most vocal voice in the United States against the current Iraq war. After the death of her son, Casey, in Iraq in 2004, Sheehan became a very vocal activist supporting troop withdrawal from Iraq. Most notably, she organized a peace vigil, "Camp Casey," outside the Crawford, Texas ranch of President George Bush while he was on a month's vacation there in August, 2005.
Cindy is one of the founding members of Gold Star Families for Peace, an organization created in 2005 to support the families of soldiers who were killed in war. The organization is explicitly political, dedicated not just to supporting families, but to ending the current war(s). The organization supports conscientious objectors and anti-war political candidates, as well as organizing peace rallies and demonstrations.
Sheehan's anti-war activities have not been limited to Camp Casey or Gold Star. She's also pledged not to pay her taxes, was arrested for protesting Bush's 2006 State of the Union Address, participated in the Bring Them Home Now Tour, and founded the Crawford Texas Peace House, among other things. However, in May 2007, Sheehan publicly announced an end to her activism, stating that she was going to dedicate her time to her remaining children.
Sheehan's retirement was short-lived. She has more recently announced her candidacy for the U.S. House of Representatives, challenging House Speaker Nancy Pelosi.