According to a post on BuzzFeed, the original demonstration permit request was for the event to be held on the National Mall.
As you can see, the Mall appears to be empty, and the crowd extends from near the Capitol almost to the White House. It looks like perhaps if the event had been held on the Mall, it may have been as large or larger than certain other events such as a recent inauguration, for example.
UPDATE: 309.2 acres of the National Mall were reserved for a local talent show involving two bicycles and jump ropes. Seems legit.
Update 2: LeaningLeftAgain reports in comments that a Freedom of Information request has been filed concerning the “local talent show”.
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