[BufordP]

Michelle Malkin has a good thread on yesterday's crowd size here.

I walked around most of the area after most of the crowd had assembled on the mall. The crowd stretched from the Capitol to about 200 hundred yards shy of the hill leading up to the Washington Monument.

How the Park Service estimates crowd size on the mall

Don't ask me how many people I thought was there. I haven't a clue.

[BufordP]

A few picks I found to give you an idea where the crowd started and ended on the mall that you can use to compare to the Park Service graphic I posted earlier in this thread.

Click on either pic to see more great crowd photos on the mall.

[Jimmy Valentine's brother]

Were you there? I didn’t see you did you see me?

[VietVet]

The Park Police estimate, based on 1 person for every 2.6 square feet would give way too high a number. That kind of density would be equivalent to a formation of troops in close order; shoulder to shoulder and belly to backbone. You might find that density in the immediate vacinity of the speakers’ podium. Otherwise, a density of one person for every 10 square feet to 36 square feet is more realistic for an outdoor crowd in warm weather. So if they estimate c. 1.2 million for a crowd that fills the Mall from the Capitol to the Washinton Monument, it would probably be closer to 90,000 to 300,000 - still a substantial number of people.

Another way to estimate the size of the crowd would be to find out how many people it would take to fill Pennsylvania Avenue from Freedom Plaza to the Capitol, and how long it would take for a person in such a crowd to walk from Freedom Plaza to the Capitol. We know it took about 3 hours for the morning crowd to march down PA Ave. Divide 3 hours by the time it takes to walk the distance, and multiply the number of people that would fill the space by the quotient and you get a rough estimate of the numbers that made the march.

Or...find out how many people rode the Metro into Washington in the morning and out of Washinton in the late afternoon. True, not all of them would have been going to the rally, but also not everyone who went to the Rally took the Metro. Compare that number to the same figures for a normal Saturday, when there is no big event going on, and you will get a rough estimate of the attendance.

VietVet (who studied Social Psychology back in the day, and estimating crowd sizes was part of the curriculum)