Police do tend to know what they’re talking about! And, to be fair, I have no crowd photos from 2009, so who knows?

Still… half a million is a HUGE crowd. That’s, like, five blocks of the Mall plus solid packing in on Capitol Hill *plus* big-time overflow into side streets.

I may be wrong, but I am fairly confident that the March took up more than one block on the National Mall. The first one that I ever attended was in 2009, just a few days of Obama’s inauguration. I went out of my way to ask a crowd control police officer what her estimate was, and she said that she wouldn’t be surprised if there were as many as half-a-million people there that year.

I don’t claim that her estimate is either official or accurate, but I suspect that she would have some experience in that field, given her line of work, and that she’d also have a fairly unbiased perspective.

I don’t know if their using the “Superdome” for Mass, and I am also pretty sure that no sporting stadium/arena in the D.C. area is called the “Superdome” (that’s in New Orleans, right?). However, they do annually use the Verizon Center, in Chinatown, for Mass. Each year, it hits a capacity of 20,000+ people.

Meanwhile, the women’s march was on a whole different level. You couldn’t move anywhere on the mall and beyond for two blocks. I’d say your figures are dead on.

I buy this. The video I’ve seen looked… very impressive. I just haven’t been able to pin it down to a figure! –James H

Such software exists, but it’s both expensive and I don’t think the algorithms it uses will do well with large crowds; it’s more designed for businesses to track foot traffic.

Of course, if anyone has access to such software, I’d be delighted to see what it comes up with for a count! –James H.

This… this makes a heck of a lot of sense. And then those numbers get picked up by other outlets and mixed up.

Yes, I can buy this. I’ll think about it some more, maybe run some numbers if there’s time. Thank you for the suggestion! –James H.