For the 243rd time, Americans are celebrating our nation’s birthday. It’s a star-spangled party, the highlight of summer for millions of us. There will be parades and picnics and politicking. And, of course, fireworks. Lots and lots of fireworks, in fact. It’s estimated Americans shell out $1 billion every July 4 on things that go boom.

Have you ever wondered why we observe America’s birthday on that particular day? Sure, the Declaration of Independence was famously approved then. But we just as easily could have picked July 2. Or July 15. Or even August 2. They all have a claim on the honor.

Although we had been engaged in an armed conflict with British redcoats for nearly 15 months by 1776, some delegates to the Second Continental Congress still hoped to patch things up with the mother country. But by early summer they reached the conclusion that England had to go. Richard Henry Lee of Virginia proposed a resolution in June declaring us an independent nation.

It was passed in a unanimous vote on July 2.

Many of our Founding Fathers thought that would be the day we commemorated. John Adams famously wrote his wife Abigail on July 3:

The second day of July, 1776, will be the most memorable epoch in the history of America. I am apt to believe that it will be celebrated by succeeding generations as the great anniversary festival. It ought to be commemorated as the day of deliverance, by solemn acts of devotion to God Almighty. It ought to be solemnized with pomp and parade, with shows, games, sports, guns, bells, bonfires, and illuminations, from one end of this continent to the other, from this time forward forever more.

But while Adams was penning those words, his colleague Thomas Jefferson was busy scratching out a formal Declaration of Independence. The task was assigned to the Committee of Five, but Jefferson did the heavy lifting. True, he borrowed heavily from Montesquieu’s The Spirit of the Laws. But he had less than 48 hours to craft a document that he knew would unleash shock waves on both sides of the Atlantic. So he did what college students under a tight deadline have done with their writing for generations: He cribbed a little.

On July 4, delegates approved the final version, which is why that date appears on the famous parchment copy now preserved in the National Archives.

On July 15, New York’s delegates received permission from state authorities back home to support the Declaration, which, one might argue, finalized the earlier vote.

The July 19 entry in the Secret Journals of Congress (published in 1821) states, “Resolved That the Declaration passed on the 4th be fairly engrossed on parchment with the title and stile of "The unanimous declaration of the thirteen united states of America" & that the same when engrossed be signed by every member of Congress.”

Many modern researchers now conclude that the Declaration was formally signed on Aug. 2, which made it official.

It seems nobody actually put their name on the Declaration on July 4. Signer Thomas McKean wrote in 1796, “No person signed it on that day nor for many days after.”

Does it really matter which date marks America’s actual birthday? Not really. Which is unusual for me, because I’m usually a stickler for historical accuracy. But in this case the significance of what the Founding Fathers did far outweighs the date on which they did it. Because each man literally laid it on the line by picking up the quill and putting their name to the Declaration. They weren’t joking when they agreed to “mutually pledge to each other our Lives, our Fortunes, and our Sacred Honor …” Had things turned out different, they might very well have wound up swinging at the end of a rope.

So happy July 2. Or 4. Or 15. Or Aug. 2. Oh well, long live the Spirit of ’76!

J. Mark Powell (@JMarkPowell) is a contributor to the Washington Examiner's Beltway Confidential blog. He is a former broadcast journalist and government communicator. His weekly offbeat look at our forgotten past, "Holy Cow! History," can be read at jmarkpowell.com.