These are just some notes.  The attendance number is getting closer to being nailed down.

This photo appears to have been taken earlier in the day.  Note that there was a festival set up in the grassy area in front of the Washington Memorial.  Eye-witnesses report that a lot of people filled the side streets and those people aren’t seen in this photo.  Also note that people came and went during the event.  There weren’t enough porta potties so people had to leave the area for a while to take care of their business.  The estimates of 60-70,000 are obviously absurd.  

The empty grass area was reserved for a festival that was to occur later in the day or on Sunday.

According to this story, the area in front of the Capitol building accommodates 240,000 people.  This area is filled in the photo, so we know that just from that area about 240,000 people attended.  Again, the estimate of 60-70,000 is absurd.  Also, if you put your mouse over the orange circles, the circle where the attendees filled the area to, it appears to show that at least 800,000 (Clinton’s inauguration) people attended.

According to accounts, the photo was taken before all the protestors had arrived,

According to Barbara Espinosa the semi-official crowd counter there were about 450,000 marchers per hour for three and a half hours.  She seems to estimate 1.2 –  1.5 million.  This means that people would have marched past her at the rate of about 125 people per second for about three hours straight.  We are waiting to find out what machine it was that counted the people. 

A large, but unknown number of people were attending without marching.

The march began at 10:00 and the mall area continued filling until at least 2:00PM

Zac Moilanen at Indiana University did a scientific calculation.  He estimated that about 1.78 Million marchers attended.  That would be about 140 marchers per second. 

A couple of twenty-something democrats gave a minimal estimate of at least 800,000 in a decently researched article. 

I believed that the Metro transit logs could be used to help estimate crowd attendance.  Heritage.org followed up on this.  I now do not believe the transit logs are useable because of variability.  When reading the Heritage.org analysis, I noted one of the comments by Kenneth Happel, the medical coordinator for the event.  He needed to know how many people were there so his staff would be prepared to respond.  Happel estimated 1 – 1.5 Million.  

Pajamas media did an estimate that at least 850,000 marched.  

Freedomworks gave an estimate of 600 – 800,000 attendees.  

Overall, my original guesstimate of about 1.2 Million still stands.

Stumble it!