In contrast to the breathless mainstream media reporting that accompanied the Obama Inauguration ("Crowded Washington Is The Place To Be", "On the Mall, a Sense of Being Part of History at Obama's Inauguration"), there was little mass media interest in Saturday's Washington DC Tea Party. Most of the 9/12 Tea Party reporting has been done by conservative bloggers. Their efforts have resulted in a good collection of stories and photos, including some things that the state-run Obama Media probably doesn't want us to see.
We may never know a precise number, but reasonable estimates seem to put the 9/12 crowd at between 500,000 and one million. An estimate of two million, allegedly reported by ABC News, was quickly retracted; on the other hand, reports by the mainstream press of merely "thousands" or "scores" of protesters were equally ridiculous. According to Rick Moran, an attempt by FreedomWorks to "meter" the protesters as they gathered came up with over 450,000 attending. Thomas Lifson quoted Dan Bana, a spokesman for the National Parks Service, as saying that the 9/12 protest was "a record ... We believe it is the largest event held in Washington, D.C., ever."
The protesters gathered in front of the Ronald Reagan Federal Building and marched down Pennsylvania Avenue to the US Capitol building. After the march, a rally was held in front of the Capitol, with protesters filling the lawn and mall between the Capitol and the Washington Monument.
Here's the time-lapse image of the march down Pennsylvania Avenue. As you can see, the march continues for some time, and Pennsylvania Avenue seems to be filled with a continuous throng of marchers, all the way from the Reagan Building to the Capitol.
Here's another photo of the march via Rob Port taken from the Capitol steps, looking back toward Pennsylvania Avenue. The photo is low res, but seems to show the lawn in front of the Capitol completely filled, with more protesters still filling Pennsylvania Avenue as far as the camera can see.
Until some good aerial photos of Saturday's march and protest finally turn up online, we won't be able to accurately estimate the size of the crowd. But when those photos become available, will be able to compare Saturday's crowd to that of previous "million visitor" events held in DC. Here are some pics that we can use for reference:
The 1995 "Million Man March":
The January 18 2003 anti-war protest held by International ANSWER. Estimated attendance 500,000.
And finally, here is a link to some nice, hi-res satellite images of President Obama's Inauguration, January 20, 2009. Attendance was estimated at between 1 million and 1.2 million.