Little-Known Fourth of July Facts (Yahoo news)

Most Americans know the Fourth of July celebrates some aspect of American Independence. But do you know exactly what the day commemorates? (Answer below*) Meanwhile, other facts surrounding the day widely known for BBQ and outdoor fun, and the patriotism that stemmed from it:
THE REVOLT: The Declaration of Independence , signed in 1776, was meant to justify a revolt against the British, with a list of charges against the British king.
THE WRITER: As Thomas Jefferson penned the Declaration, Britain's army was on its way toward to New York Harbor. It began:
"When in the course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation."
THE WAR: The Declaration of Independence was signed by 56 men representing the 13 colonies. The moment marked the beginning of all-out war against the British. The American Revolutionary War is said to have started in 1775, however. The Declaration was signed more than two years after Boston officials refused to return three shiploads of taxed tea to Britain, fueling colonists to dump the tea into the harbor in what became the infamous Boston Tea Party.
KNOCK-ON EFFECTS: Several countries used the Declaration of Independence as a beacon in their own struggles for freedom. Among them, France. Then later, Greece, Poland, Russia and many countries in South America. [How Other Countries Celebrate Independence]
SING PROUD: "Yankee Doodle," one of many patriotic songs in the United States, was originally sung prior to the Revolution by British military officers who mocked the unorganized and buckskin-wearing 'Yankees' with whom they fought during the French and Indian War.
SING PROUDER: The "Star Spangled Banner" wasn't written until Francis Scott Key wrote a poem stemming from observations in 1814, when the British relentlessly attacked Baltimore's Fort McHenry during the War of 1812. It was later put to music and not decreed the official National Anthem of the United States until 1931.
DEATH ON THE FOURTH OF JULY: Three U.S. presidents actually died on July 4. Two of them passed away within hours of each other on July 4, 1826: John Adams and Thomas Jefferson. The two had been political rivals and then friends later in life. The other to share the distinction was James Monroe, who died July 4, 1831.
*Answer: The Fourth of July commemorates the adoption of the Declaration of Independence. It was initially adopted by Congress on July 2, 1776, but then it was revised and the final version was adopted two days later.