Back when they wrote the U.S constitution, the country's founding father's come up with 35 words and oath, the same one that every president says when he takes office or starts a new term. The same one the U.S chief Justice John Roberts gave to president Obama yesterday.

"Please raise your right hands and repeat after me. I, Barack Hussein Obama, do solemnly swear."

"I, Barack Hussein Obama, do solemnly swear."

"That I will faithfully execute."

"That I will faithfully execute."

"The office of president of the United States."

"The office of president of the United States."

"And will to the best of my ability."

"And will to the best of my ability."

"Preserve, protect and defend."

"Preserve, protect and defend." 

"The constitution of the United States."

"The constitution of the United States." 

"So help you God."

"So help me God."

"Congratulation, Mr.president."

That isn't the first time president Obama's taking that oath this week, the constitution says that a president's term ends and the next one starts at noon on January 20th. That was Sunday, and that's when chief Justice Roberts give president Obama the oath in the White House. Not the first time something like that has happened, in fact, it's the seventh time. Whenever January 20th has fallen on a Sunday in an inauguration year. Public ceremony has been moved to Monday. Organizers are expected around 800,000 people to fill the National Mall for that ceremony. The platform at the U.S capital building was filled wit former presidents, supreme court justices and members of Congress. The ceremony included some stars as well like Beyonce who performed the National Anthem. And Kelly Clarkson who sang "My Country, Tis of Thee".

Including Barack Obama, 17 presidents have given a second inaugural address. The theme for yesterday's inauguration was faith in America's future. And in his speech, president Obama talked about what lies ahead for the country.

"America's possibilities are limitless, for we possess all the qualities that this world without boundaries demands. Youth and drive, diversity and openness, and endless capacity for risk and gift for reinvention. My fellow Americans, we are made for this moment and we will seize it so long as we seize it together."

The inaugural day and its traditions don't end in with the swearing in ceremony, afterward, the president, congressional leaders sat down for a ceremonial lunch. Then the first family led the way from the capital back to the White House in the inaugural parade, that included floats and marching bands from across the country. And an inauguratoin day wrapped up last night with parties to honor the president.

Going back to George Washington, there had been 57 presidential inaugurations. It gives up a lot of interesting inaugural info. President Obama's speech yesterday was around 2,000 words long. The shortest inaugural address was George Washington's second one, just 135 words. The longest, nearly 85,000, William Henry Harrison spoke for an hour and 45 minutes in an snowstorm, without wearing a coat or hat. He died one month later of pneumonia. There's been 57 inaugurations, but presidents have taken the oath of office 71 times. That's because of situations like this year when president Obama took it twice. One man has been on both sides of that oath, William Taft took it in 1909, then he administrated the oath in 1925 and 1929. Because he was the chief justice of the United States. How about some inaugural technological inauguration trivia? Say that three times fast. First inauguration, known to be photographed, James Buchanan, in 1857, first one on TV, Harry Truman, in 1949. And first inauguration broadcast on the internet, Bill Clinton, in 1997.