Americans Celebrate the Fourth of July

Audience members join arms as the Boston Pops play "God Bless America" during their Fourth of July Concert at the Hatch Shell in Boston, July 4, 2013

Independence Day fireworks light the sky over Washington, July 4, 2013.

Fireworks light up the Empire State Building along the Manhattan skyline during Macy's 37th Annual Fourth of July fireworks show, July 4, 2013, in New York.

Matthew Usher looks up at the clouds to check for rain as he waits for a concert to start as part of the Independence Day activities, July 4, 2013, in Nashville, Tennessee.

Fireworks explode over the Philadelphia Museum of Art during an Independence Day celebration, July 4, 2013, in Philadelphia.

Residents and visitors of Alexander's Lake sit out on their docks and in small boats as they watch neighborhood fireworks as they celebrate Independence Day, July 4, 2013, in Dayville, Connecticut.

Fireworks for Independence Day are seen on the New Jersey shore, July 3, 2013.

Fireworks light the sky over the U.S. Capitol, left, the Washington Monument and the Lincoln Memorial during Fourth of July celebrations in Washington, July 4, 2013.

Visitors to the Statue of Liberty disembark onto Liberty Island from the first ferry to leave Manhattan, July 4, 2013.

A girl poses as they visit the Statue of Liberty and Liberty Island during its reopening to the public in New York, July 4, 2013. The Statue of Liberty closed in October during Superstorm Sandy.

President Barack Obama holds a baby as he greets members of the military and their families during a Fourth of July celebration on the South Lawn of the White House in Washington, July 4, 2013.

A U.S. soldier cuts into a cake during Fourth of July celebrations at the Bagram airbase, north of Kabul, Afghanistan, July 4, 2013.

A family buys fireworks at a TNT Fireworks stand in Monterey Park, California, July 2, 2013.

Heavy traffic during the Fourth of July weekend backs up the Chesapeake Bay Bridge in Maryland, the main route from Washington, DC to beaches along the Delmarva Peninsula.

A U.S. flag, in the shape of the country, is unfurled in the outfield before a baseball game between the Washington Nationals and the Milwaukee Brewers at Nationals Park in Washington, July 4, 2013.