See video from the newswire.

Today [2004-10-02] several hundred (perhaps a couple thousand in attendence by the end) people marched from Arlington National Cemetery to The Ellipse, south of the White House. They carried many of the hundreds of cardboard coffins (the rest laid out on The Ellipse by volunteers ahead of the march) from the cemetery, across the Memorial Bridge, past the Lincoln memorial and down Constitution Avenue.

The coffins represent the American military deaths, in excess of 1,000 ( http://cryptome.org/mil-dead-iqw.htm, includes 56 afghan casualties, but Iraq sum still well exceed 1k and climbs ) in the Iraq war alone; without including Afghanistan, mercenaries, contractors, and those unaffiliated with the occupation but killed in war-zones with American involvement. The minority of flag-draped coffins represents the proportion of American military dead to all the other losses -- Iraqi, non-military, other military, etc, in Iraq.