Why July 4?

From Livescience.com:

John Adams predicted in a letter to his wife Abigail that Americans would celebrate their Independence Day on July 2. Off by two days - not too bad for government work.

On July 2, 1776, Congress adopted the Declaration of Independence, signed only by Charles Thompson (the secretary of Congress) and John Hancock (the presiding officer). Two days later Congress approved the revised version and ordered it to be printed and distributed to the states and military officers. The other signatures would have to wait.

Many actually viewed the Declaration of Independence as a yawner - a rehashing of arguments already made against the British government. John Adams would later describe the Declaration as "dress and ornament rather than Body, Soul, or Substance." The exception was the last paragraph that said the united colonies "are and of Right ought to be Free and Independent states" and were "Absolved of all Allegiance to the British Crown."

For Adams, it was the momentum towards achieving American independence initiated on July 2 that future generations would consider worth celebrating, not the approval of this document on July 4.

Interestingly, the pomp and circumstance that many Americans presume took place on July 4, 1776, actually occurred days to weeks afterwards.

The Philadelphia Evening Post published the Declaration's full text in its July 6 newspaper. And the Declaration of Independence was publicly read from the State House in Philadelphia on July 8. Later that day, it was read in Easton, PA, Trenton, NJ, and to the local embryonic militia to provide much-needed inspiration against the formidable British.

The shouting and firing of muskets that followed these first public readings represent America's first celebrations of independence.

As copies spread, the Declaration of Independence would be read at town meetings and religious services. In response, Americans lit bonfires, fired guns, rang bells, and removed symbols of the British monarchy.

The following year, no member of Congress thought about commemorating the adoption of the Declaration of Independence until July 3 - one day too late. So the first organized elaborate celebration of independence occurred the following day: July 4, 1777, in Philadelphia. Ships in the harbor were decked in the nation's colors. Cannons rained 13-gun salutes in honor of each state. And parades and fireworks spiced up the festivities.

Fireworks did not become staples of July 4 celebrations until after 1816, when Americans began producing their own pyrotechnics and no longer relied on expensive fireworks from across the pond.

Since 1777, the tradition of celebrating America's independence on July 4 has continued.