Early indications were that easily more than a million people, and perhaps 2 million, may have journeyed to the National Mall and surrounding areas for the swearing-in of the first African-American president.
The National Park Service - long relied on to calculate crowds for large Washington events - is expected to provide a firmer estimate later in the week, according to a spokesman. Crowd counting is an inexact and controversial business. Experts cautioned that it would be difficult to quickly calculate the size of the gathering.
The Washington Post reported a crowd
of 1.8 million.
The park service has not done official estimates in more than a decade, obeying an order by Congress to stop in the aftermath of controversy over how many people attended the 1995 Million Man March. Then, estimates varied from 400,000 to more than 1 million.
In 1981, President Ronald Reagan's inauguration drew about 500,000 people; President Bill Clinton's 1993 inauguration drew about 800,000, according to the park service.