OK, so after seeing the very impressive photos of the Portland Obama rally, I got curious.

What are the largest gatherings in history?

Well, according to the trusty wiki:

http://en.wikipedia.org/wiki/List_of_largest_gatherings_in_history

They aren't in North America!

I did see that Kerry pulled in an even larger crowd than Obama in Madison WI in 2004 (est 80,000). But that might be splitting hairs. Also, that was in the general election, and he had a real rock star as an attraction, Bruce Springsteen.

Obama pulled 'em in all on his own.

I find it very interesting the 2003 global anti-war rally in the run up to the conquering of Iraq by the US, wasn't nearly as big outside the "Western democracy" countries, as was the 2007 global anti-poverty rally.

Certainly, far more of the globe has a stake in the latter than the former, so it makes perfect sense.

I haven't found statistics of US presidential candidate rallies. I'll see if I can keep looking. Funerals too, would tell a story, ie the funerals of the presidents probably had hundreds of thousands involved but probably not in one place.