As Barack Obama was sworn in as president of the United States Monday, the National Mall in Washington, D.C., filled with hundreds of thousands of people who had come to see the official beginning of the first African-American president's second term in office -- on the same day that the nation celebrated Martin Luther King Day.

In a speech that's already being widely recognized as a high moment in the history of American political oratory, Obama laid out the challenges ahead, but used the refrain "We, the people," from the preamble to the Constitution to underscore that it's up to citizens to set the course of the nation.

This is a set of images depicting the faces of the Americans who came to their capital to see the inauguration.

Capitol Obama Second Inaugural
Two attendees pose for a photo with Monday's Washington Post as the sun rises behind the Capitol building. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
Arnold Monroe of Scramento, Calif. waves American flags on the National Mall. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
Stephen McCarter of Chesterfield, Va. holds a flag. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
A visitor holds a memento tote back with the words "Made in China" on it. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
Amber Bokai of Silver Springs, Md. takes a photo using her iPhone. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
Cheryl Jones of Arlington, Va. shows off a homemade Martin Luther King Jr. pin Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
People take photos of Matt Duffy taking a photo. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
Visitors use binoculars to watch the Presidential Inauguration. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
Nhat Tran of Raleigh, N.C., rear, photobombs a group photo of LeadAmerica students. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
A visitor flies an Equality flag. Obama made several references to gay rights in his inaugural address and is expected to make the issue a major part of his second term. Elijah Nouvelage/International Business Times
National Mall Obama Second Inaugural
Visitors wave flags upon the first glimpe of Sasha and Malia Obama on monitors. Elijah Nouvelage/International Business Times
Barack obama