American Independence may in part be something to celebrate. If Edmund Burke, the arch conservative, Ben Franklin, the arch moderate, and Tom Paine, the arch radical, could all agree on the need for the Americans to break away from the British, then they must have a point. No doubt, the English were heavy handed. True, fundamentally, the English did seem to have a point that the American should pay at least a fraction of the taxes that the people back in England had to pay in order to cover the costs of defending the colonies from the French and Indians. Still, the war was justified due to the lack of compromise on the English side.
But was American independence good or bad? It's hardly a slam dunk either way. Let's think about a few things:
1) The Indians were worse off.
The victory of the Americans over the British was a catastrophe for almost every Indian nation in what is now the United States and not great for some in Canada. From the founding of the first colony at Jamestown in 1607 to the end of the revolutionary war in about 1783, English speaking colonists had gotten as far west as Albany New York and not much farther. In half the time after the revolution, colonists were on the Pacific ocean. Being able to put a national army on the field without having to consider British imperial priorities and financing was key to this.
Slower conquest of the west would have been a good thing not just for the Indians. The pattern of settlement would have been better, more planned, and American towns and cities in the west would be more logically laid out than they are now.
With better planning, public transportation would be easier, we would be less of a car country and contribute less carbon to the atmosphere.
2) The slaves were worse off.
A high percentage of people in the 13 colonies were slaves. Slavery ended 30+ years earlier in the British Empire without a civil war than it did in America. If the Americans and the British could have worked out a compromise in 1776 and the American colonies remained part of the commonwealth, slavery may have ended earlier with less bloodshed.
You cannot say the 20 million people spending 30 years in slavery is trivial. True, if the southerns were part of the Empire, they would have objected to emancipation in 1833. But the planters in the West Indies were unable to stop the process. And American pro-slavery southerns were not as well organized politically the 1820s as they would be in the 1840s and 50s.
Plus, if America were part of the empire, northern abolitionists would have had some sway as well, countering the pro-slavery forces.
3) The value of political stability may be overrated in one way.
Unlike the Spanish colonies, the English colonies were able to forma single, powerful, stable government: no coups, no chaos, law and order and constitutional government for 238 years, more or less. There is one exception: the Civil War. But that exception is huge. More people were killed in the American Civil War than in every class of political violence in all of central and south America, the Caribbean combined for all of history from Cortez to Chavez: more died violently in the American Civil War (not including the miners in Potosí, that's not war...)
In fact, we could throw in all the Americans (US) killed in all wars except the Civil War and the tally for the Civil War would still be higher. If American Independence lead to the Civil War, July 4 has some explaining to do.
True, long periods of stability allow development. But development can lead to industrialized warfare, which then wipes out a staggering number of people.
4) The individual liberties we admire are actually British anyway.
One way or another, if the colonies had stuck it out in the Empire, the Americans would have eventually gotten home rule and independence from Great Britain like the other white majority colonies, like Australia and Canada. True, the Australians, New Zealanders and South Africans might have gotten better treatment due to the example of the Americans, but it's hard to imagine some kind of commonwealth not being established if only the founding fathers had stuck it out.
5) Home rule, when it came, would have included Canada.
If America could have sucked up a little high handed administration for just a little while longer, and avoided war, there would have been no exodus of royalists to Canada. The cultures of Canada and American would not have diverged as much. With a peaceful transition to home rule, all the of the American territories would been part of a single unit.
With Canada and America as a single unit, the power of the reactionary and racist south would be far less. No gun violence. No racist code word politics. That crap wouldn't work in a country with Ontario, Quebec, Vancouver, etc. as members of the country. The north would be just that much stronger and politically.
Plus, without the Civil War, the south would not have ended up so unique.
So, slavery ended peacefully in 1833, no civil war, no reactionary politics, better integration of Indians, longer periods of freedom for Indians...
Now, what is it we were celebrating on July 4 again?