Obama announces new EPA protection of waterways

U.S. President Barack Obama attends the Nuclear Security Summit in the Hague, Netherlands, in March 2014. As Obama's second term nears its close, here's a look at some key moments of his administration.

First lady Michelle Obama brushes specks from the coat of then-Sen. Obama in Springfield, Illinois, just before he announced his candidacy for President in February 2007. Their daughters Malia, left, and Sasha wait in the foreground.

Obama appears on "Meet the Press" with Tim Russert, right, in Des Moines, Iowa, in November 2007.

Obama shakes hands with supporters after addressing a rally in Concord, New Hampshire, in January 2008.

Obama gives a speech at the National Constitution Center in Philadelphia in March 2008.

Obama speaks at the 2008 Democratic National Convention in Denver.

Obama stands on stage in Chicago with his family after winning the presidential election on November 4, 2008.

Obama poses in the Oval Office with several former U.S. Presidents in January 2009. From left are George H. W. Bush, Obama, George W. Bush, Bill Clinton and Jimmy Carter.

Obama is sworn in by Chief Justice John Roberts as the 44th President of the United States on January 20, 2009.

As retired military officers stand behind him, Obama signs an executive order to close down the detention center at Guantanamo Bay, Cuba, in January 2009.

Obama and Vice President Joe Biden look at solar panels as they tour the solar array at the Denver Museum of Nature and Science on February 17, 2009. That same day, Obama signed the American Recovery and Reinvestment Act.

A soldier hugs Obama during his surprise visit to Camp Victory just outside Baghdad, Iraq, in April 2009.

Obama bends over so the son of a White House staff member can pat his head during a visit to the Oval Office in May 2009. The boy wanted to know if Obama's hair felt like his.

Obama kisses Sonia Sotomayor's cheek after announcing her as his nominee for Supreme Court justice in May 2009.

Palestinian security forces in Jenin, West Bank, listen to Obama speak from Cairo University in Egypt in June 2009. The Palestinian Authority hailed as a "good beginning" Obama's speech to the Muslim world in which he reiterated his support for a Palestinian state.

Obama and the first lady meet with Pope Benedict XVI in Vatican City in July 2009.

Obama hosts the Apollo 11 astronauts -- from left, Edwin "Buzz" Aldrin, Michael Collins and Neil Armstrong -- in the Oval Office on July 20, 2009. It was the 40th anniversary of the moon landing.

Police Sgt. James Crowley, second right, of Cambridge, Massachusetts, speaks with Harvard Professor Henry Louis Gates Jr., second left, alongside Obama and Biden as they share beers on the South Lawn of the White House in July 2009. The so-called Beer Summit was held after Crowley arrested Gates at his own home, which sparked tensions and racial furor.

Obama salutes during the transfer of Sgt. Dale R. Griffin at Dover Air Force Base in Dover, Delaware, in October 2009. Obama traveled to the base to meet the plane carrying the bodies of 18 U.S. personnel killed in Afghanistan.

Obama walks along the Great Wall of China in November 2009.

Obama delivers a speech after receiving the Nobel Peace Prize in Oslo, Norway, in December 2009.

Obama and former Presidents Clinton and George W. Bush walk to the White House Rose Garden to speak about relief efforts for earthquake-stricken Haiti in January 2010.

First daughters Sasha and Malia Obama play in the snow with their father after a snowstorm hit Washington in February 2010.

Obama's signature on the Affordable Care Act is seen at the White House in March 2010.

Obama throws out the opening pitch before a baseball game between the Philadelphia Phillies and the Washington Nationals in April 2010.

Obama and his daughter Sasha swim in Panama City Beach, Florida, in August 2010, to encourage people to come back to the Gulf Coast after a devastating oil spill.

Obama laughs as he makes a statement on his birth certificate in April 2011. Obama said he was amused over conspiracy theories about his birthplace, and he said the media's obsession with the "sideshow" issue was a distraction in a "serious time."

Obama, Biden, Secretary of State Hillary Clinton and members of the national security team receive live updates on the mission to capture or kill Osama bin Laden on May 1, 2011.

U.S. Marines watch from Afghanistan as Obama announces the death of bin Laden on May 2, 2011.

Obama enjoys a pint of Guinness in his ancestral home of Moneygall, Ireland, in May 2011.

Obama and the first lady meet with Britain's Prince William and Catherine, Duchess of Cambridge, at Buckingham Palace in May 2011.

Obama and Missouri Gov. Jay Nixon walk together in May 2011 during a tour of the tornado devastation in Joplin, Missouri.

Obama delivers remarks to troops and military families at Fort Bragg, North Carolina, on December 14, 2011, marking the exit of U.S. soldiers from Iraq.

Obama pays for a dog toy as he shops with his dog Bo at a PetSmart in Alexandria, Virginia, in December 2011.

Obama sits on the famed Rosa Parks bus at the Henry Ford Museum in Dearborn, Michigan, in April 2012.

British Prime Minister David Cameron, Obama, German Chancellor Angela Merkel and others watch the overtime shootout of the Champions League final between Chelsea and Bayern Munich in a conference room at Camp David, Maryland, during a G-8 Summit in May 2012.

Obama sits in his chair during a Cabinet meeting in July 2012. This image was tweeted by his official Twitter account in August 2012 in response to Clint Eastwood's "empty chair" speech at the Republican National Convention. The tweet simply said, "This seat's taken."

Obama casts a shadow in this picture as he accepts the 2012 Democratic nomination for President during the final day of the Democratic National Convention in September 2012.

Obama and Republican presidential candidate Mitt Romney participate in the first presidential debate of the 2012 election.

Obama celebrates on stage in Chicago after defeating Romney on Election Day in 2012.

Obama pauses during his speech at a memorial service for the victims of the Sandy Hook Elementary School massacre in De