The Obamas began their day of public events by leaving Blair House for a service at St. John's Church in Lafayette Square, so-called the Church of Presidents where commanders in chief dating back to James Madison have knelt and bowed their heads before taking the oath of office.
The Obamas rode in the new presidential limo with the simple license plate number of "USA 1."
Obama and his wife sat in the center of the first row as the congregation stood and sang a hymn. At one point during the ceremony, Joel Hunter instructed those sitting near Obama to place their hands on his shoulders and head as a "spiritual means of giving grace."
The service's main speaker, Bishop T.D. Jakes, spoke of the many trials Obama will face, told Obama that "God goes with you" and then added that his 14-year-old son would probably offer Obama a different benediction.
"He probably would use Star Trek instead, and so I say, 'May the force be with you,'" Jakes said confusing "Star Trek" with "Star Wars."
The service was the first event of a day filled with traditions and significance, but those hallowed acts took on the added historic power -- and for many bolster the proceedings' sense of exhilaration -- as they are carried out for the first time in 220 years by an African-American.
More than a million people flocked to the National Mall to witness history.
They poured into the Mall viewing area throughout the night, smiling, waving and bundled up against the frigid overnight temperatures. Some even came chanting "Obama, Obama" and "Yes, we can."
The darkness glittered with the flash of thousands of cameras as attendees turned the long wait into an impromptu party.
The areas closest to the steps were packed well before sunrise, and by the time the sun came up the Mall was a sea of people.
Still they came, lined up for blocks as they patiently waited to get cleared by the massive security cordon, and subways from surrounding suburbs were jammed with people hoping to squeeze into the Mall party. By mid-morning, the National Parks Service stopped allowing people onto the Mall and redirected them to the Washington Monument grounds.
As the throngs gathered outside, Bush carried out one of his last acts and one of the oldest presidential traditions. He wrote a note to the incoming president and left it in the top drawer of the Oval Office desk. By tradition, the contents of those notes are never revealed.
And across the street in Blair House, Obama received the first of what will become a near daily exercise: his national security briefing. At this first briefing, the military aide who carries the briefcase with nuclear codes -- known as the "football" -- instructed Obama on the protocol surrounding it.
A long weekend of concerts and celebrations were prelude to today's inauguration.
Obama's history-making presidency comes at a historically critical time, as the United States faces the worst economic crisis since the Great Depression.