IN PHOTOS: Fireworks, parades and protests mark US I-Day

People across the United States gathered on Thursday for parades, picnics and fireworks at Independence Day celebrations, held under unprecedented security following the Boston Marathon bombings.

Spectators waving U.S. flags and wearing red, white and blue headed for public gatherings in Boston, New York, Washington, Atlanta and other cities under the close watch of police armed with hand-held chemical detectors, radiation scanners and camera surveillance, precautions sparked by the deadly April 15 bombings.

We present stunning images from across the United States of America which celebrated its 237th Independence Day on Thursday.

In this photograph, Independence Day fireworks are seen lighting the sky over the U.S. Capitol, Washington Monument and Lincoln Memorial in Washington, DC, on Thursday.

The iconic Washington skyline serves as a backdrop for the U.S. national birthday celebration each year.

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U.S. President Barack Obama and First Lady Michelle Obama greet guests during Independence Day celebrations on the South Lawn of the White House in Washington.

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A demonstrator holds a sign with a photograph of former U.S. spy agency NSA contractor Edward Snowden and the word "HERO" during Fourth of July Independence Day celebrations in Boston, Massachusetts.

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The Haig family stands for the United States pledge of allegiance before a public reading the United States Declaration of Independence, part of Fourth of July Independence Day celebrations, in Boston, Massachusetts.

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People stand in the middle of 44th St at Times Square to watch Independence Day fireworks in New York.

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The 3d U.S. Infantry, traditionally known as 'The Old Guard', perform during a ceremony to reopen the Statue of Liberty and Liberty Island to the public in New York July 4, 2013.

Under steamy summer skies, tourists in New York flocked to ferries headed for the Statue of Liberty, re-opening with an Independence Day ceremony after closing in October as Superstorm Sandy approached.

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Re-enactors march away from the Old State House following a public reading of the United States Declaration of Independence, part of July Fourth Independence Day celebrations, in Boston, Massachusetts.

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

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A woman watches the fireworks for Independence Day in Seaside Heights, New Jersey.

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A man with the American flag painted on his face poses for a portrait as he celebrates the Fourth of July Independence Day celebrations in Prescott, Arizona.

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National Guard troops patrol the oval in front of the Hatch Shell ahead of the city's Fourth of July Independence Day celebrations in Boston, Massachusetts.

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People take part in an Independence Day parade in Ridgefield Park, New Jersey

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A child attends a ceremony to reopen the Statue of Liberty and Liberty Island to the public in New York on July 4, 2013 on the occasion of the Independence Day.

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