Estimates are that the Promise Keepers' rally filled the Washington D.C. mall with more than a million people in 1997!
Dr. Martin Luther King Jr. delivered his "I have a Dream" speech on August 28, 1963 before a crowd of 250,000+.
No one knows how many people were at Woodstock in 1969. The estimates are 500,000+. Don't look for me here. I try to avoid crowds!
Estimates are that the Promise Keepers' rally filled the Washington D.C. mall with more than a million people in 1997!

Sheehan was scheduled to appear at noon on the front lawn of the Capitol. It couldn't be called a rally; just a handful of Washington supporters showed up on the lawn to join dozens of journalists. The real stars were the TV crews; 15 cameras were set up in a semi-circle in front of a bank of microphones where Sheehan would speak.
But noon came and went, with no Sheehan. A young man named Ryan Fletcher, from an organization called the Mintwood Media Collective, paced around, a cell phone to his ear, getting updates from the three buses in which Sheehan and her supporters were riding. Less well-known than Fenton Communications, which advised Sheehan last month during her protest near the president's ranch in Crawford, Texas, Mintwood describes itself as "a worker-owned and operated public relations firm born in the aftermath of the mobilization against the International Monetary Fund and World Bank in Washington DC, April 16th and 17th, 2000." During that protest, Mintwood boasts, it came up with "a comprehensive media strategy that succeeded in placing stories on the front pages of major newspapers, on local and national television and radio, and Internet information sites worldwide." It promises to do the same for clients today.