Obama's first inauguration in 2009 drew an estimated 1.8 million people, the largest gathering in the history of Washington, D.C. The crowd witnessed the first person of color take the oath of office.
No one expects a similar gathering this time around. Not even close.
Washington, D.C.'s Metro system expects to carry 500,000 to 800,000 people to the public inauguration. If more than 500,000 people show up it would be the biggest crowd to ever witness the inauguration of a second-term president and the fourth largest inaugural gathering in U.S. history.
Only three have attracted crowds larger than 500,000 people. They are Obama's, Lyndon Johnson's in 1965 (1.2 million) and Bill Clinton's in 1993 (800,000).
By the numbers • Inauguration trivia
4 • Number of times President Obama will have been sworn in, including a make-up swearing in during his 2009 inauguration because of a bumbled exchange between Chief Justice John Roberts and the president. The only other president who can match that is Franklin Roosevelt, who was elected to four terms.
7 • Times that Inauguration Day has fallen on a Sunday, including this inauguration. All of the public ceremonies have been shifted to Monday, the last being in 1985 with Ronald Reagan's second inauguration.
135 • Words in the shortest inaugural address, delivered by George Washington at his second inauguration.
8,500 • Words in the longest inaugural address, delivered by William Henry Harrison, who served the shortest time of any U.S. President: one month.
By the numbers • Today's inauguration
1.5 • Length, in miles, of the inaugural parade route, between the Capitol and the White House.
58 • Groups marching in the inaugural parade, which includes a Latino dance group from Utah.
1,100 • Portable toilets being set up around the parade route.
2 • Official inaugural balls, down from 10 in 2009.
40,000 • People expected to attend the balls.
300 • American flags being hung around the nation's capital.