Comment: This is circulating through our school district and I cannot find it's origin. Is this an actual photo of an actual event in Washington, DC? The person who is linking this photo to school websites is notorious for doctoring images for political purposes.
My wife and I have lived in the DC area for almost 30 years. We do not recall such an exhibition ocurring on the Mall, but we don't know everything that happens over there. There is a tower crane behind the Washington Monument, so that dates the pictures to roughly the last three decades. There have been several wars during that time period, and the event could relate to any of them. The organizers of the event would have needed a permit from the Park Service, so that's one possible source of verification.