How many people attended inauguration?

Congress took up the issue in 1997 and actually prohibited the Park Service from conducting crowd estimates. So this year, because Tuesday’s “events were historic in nature to our nation,” Line said, his agency would use the figure ascertained by someone else.

That reported figure, Line said, came from the Washington Post, which reported on Wednesday “a crowd that some estimates put at nearly 1.8 million.” And that report, according to the paper, came from an unsourced official.

Maggie Daniels, a George Mason University professor of tourism and events management who has conducted research on crowded Mall festivities, said the 1.8 million figure seems too big, but precise analyses remain to be completed.

“I tend to think it’s closer to about 1 million” on the Mall, she said.

Clark McPhail, an expert in crowd counting and professor emeritus at the University of Illinois, said that 1.5 million people spread from the west lawn of the Capitol to the far end of the reflecting pool would have a consistent density equivalent to packing nearly 2,000 people on a basketball court.

DCE

Maybe it's all media hype.