But don’t forget there is a 6,000 seat mosque in Washington, DC that was conceived of in 1944 and completed construction in 1954 and dedicated by Ike in 1957.
http://en.wikipedia.org/wiki/Islamic_Center_of_Washington
I almost forgot!
There’s a mosque at Quantico.
http://www.wnd.com/2006/12/39297/
http://www.washingtonpost.com/wp-dyn/content/article/2006/06/06/AR2006060601529.html