Millions of Americans are celebrating their country's 240th anniversary of independence from Britain with traditional fireworks displays, parades, concerts and barbecues, amid heightened security following recent terror attacks in Bangladesh and Turkey.
Law enforcement officials say they have not received any specific threats against the United States, but heavily armed police officers, many accompanied by dogs, are patrolling airports, and train and bus stations.
Security has been enhanced in Washington, New York City and Chicago where hundreds of thousands of people gather annually to watch fireworks, listen to music and have picnics.
More than 1,200 newly sworn-in police officers in New York City are busy at work, along with the city's newly formed Critical Response Command, a heavily armed counter-terrorism force.
About 5,000 police are patrolling the streets of Chicago this extended holiday weekend, which is traditionally one of the most violent. Gun-related murders in Chicago have spiked this year. This weekend, at least 24 people have been shot, three fatally.
Eight security checkpoints are in place along Washington's Mall, where officers are searching all bags and coolers, and confiscating alcohol and marijuana.
The Department of Homeland Security is reminding citizens to be alert and to report anything unusual to authorities.
President Barack Obama is commemorating the holiday at the White House, where the United Service Organization, which serves military families, is hosting a program featuring musical guests. While the planned picnic has been canceled due to rain, scheduled performances by singer Janelle Monae and rapper Kendrick Lamar will go on as planned indoors.
During his weekly radio address, Obama said celebrating Independence Day has become one of his favorite traditions. "We get to celebrate our freedoms while doing what we can to honor all those who served and sacrificed to make that freedom possible," Obama said.
A short distance away on the West Lawn of the U.S. Capitol, the "Capitol Fourth Concert" will be held, featuring legendary musical performers Smokey Robinson and Kenny Loggins.
An historical feat may be accomplished this Independence Day at New York's Coney Island, where the traditional hot dog eating contest takes place and Joey Chestnut will attempt to regain his Mustard Yellow International Belt. He set a world record two years ago by eating 69 hot dogs in 10 minutes, but lost it last year after eight straight victories.
In Austin, Texas, 10,000 people will gather at a race track to attend a party hosted by country music legend Willie Nelson.
In keeping with tradition, many communities and individuals are lighting fireworks. Consumers spent $755 million dollars in 2015 on fireworks for personal use, a $60 million increase from the previous year, according to the American Pyrotechnics Association.
But traditional fireworks displays may not be an option this year in some parts of the United States. Fireworks have been banned in drought stricken Santa Barbara County, California and in some other dry communities in Western states.
On July 4, 1776, representatives of the 13 American colonies officially adopted the Declaration of Independence that announced the severing of ties with Britain.
The rebellion had begun the previous year and would continue until the United States and Britain signed the Treaty of Paris in 1783, which formally recognized the independence of the United States of America.
Although the Declaration of Independence states, "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their creator with certain inalienable rights, that among these are life, liberty and the pursuit of happiness," the document was drafted by Thomas Jefferson, a slave owner who later became the third U.S. president.
Jefferson was not the only slave owner to sign the document. About one-third of the signers of the Declaration of Independence, from the north and the south, owned or had owned slaves. George Washington, who also signed the decree and later became the country's first president, owned nearly 125 slaves, whom he freed in his will.
John Adams, the second president and Washington's vice president, did not own slaves, but supported a gradual process of abolishing slavery.
The issue of slavery was not settled until the Civil War ended nearly 80 years after the signing of the Declaration of Independence.