This July 4, let's not mince words: American independence in 1776 was a monumental mistake. We should be mourning the fact that we left the United Kingdom, not cheering it.

Of course, evaluating the wisdom of the American Revolution means dealing with counterfactuals. As any historian would tell you, this is a messy business. We obviously can't be entirely sure how America would have fared if it had stayed in the British Empire longer, perhaps gaining independence a century or so later, along with Canada.

But I'm reasonably confident a world in which the revolution never happened would be better than the one we live in now, for three main reasons: Slavery would've been abolished earlier, American Indians would've faced rampant persecution but not the outright ethnic cleansing Andrew Jackson and other American leaders perpetrated, and America would have a parliamentary system of government that makes policymaking easier and lessens the risk of democratic collapse.

Abolition would have come faster without independence

The main reason the revolution was a mistake is that the British Empire, in all likelihood, would have abolished slavery earlier than the US did, and with less bloodshed.

Abolition in most of the British Empire occurred in 1834, following the passage of the Slavery Abolition Act. That left out India, but slavery was banned there, too, in 1843. In England itself, slavery was illegal at least going back to 1772. That's decades earlier than the United States.

This alone is enough to make the case against the revolution. Decades less slavery is a massive humanitarian gain that almost certainly dominates whatever gains came to the colonists from independence.

The main benefit of the revolution to colonists was that it gave more political power to America's white male minority. For the vast majority of the country — its women, slaves, American Indians — the difference between disenfranchisement in an independent America and disenfranchisement in a British-controlled colonial America was negligible. If anything, the latter would've been preferable, since at least women and minorities wouldn't be singled out for disenfranchisement. From the vantage point of most of the country, who cares if white men had to suffer through what everyone else did for a while longer, especially if them doing so meant slaves gained decades of free life?

It's true that had the US stayed, Britain would have had much more to gain from the continuance of slavery than it did without America. It controlled a number of dependencies with slave economies — notably Jamaica and other islands in the West Indies — but nothing on the scale of the American South. Adding that into the mix would've made abolition significantly more costly.

But the South's political influence within the British Empire would have been vastly smaller than its influence in the early American republic. For one thing, the South, like all other British dependencies, lacked representation in Parliament. The Southern states were colonies, and their interests were discounted by the British government accordingly. But the South was also simply smaller as a chunk of the British Empire's economy at the time than it was as a portion of America's. The British crown had less to lose from the abolition of slavery than white elites in an independent America did.

The revolutionaries understood this. Indeed, a desire to preserve slavery helped fuel Southern support for the war. In 1775, after the war had begun in Massachusetts, the Earl of Dunmore, then governor of Virginia, offered the slaves of rebels freedom if they came and fought for the British cause. Eric Herschthal, a PhD student in history at Columbia, notes that the proclamation united white Virginians behind the rebel effort. He quotes Philip Fithian, who was traveling through Virginia when the proclamation was made, saying, "The Inhabitants of this Colony are deeply alarmed at this infernal Scheme. It seems to quicken all in Revolution to overpower him at any Risk." Anger at Dunmore's emancipation ran so deep that Thomas Jefferson included it as a grievance in a draft of the Declaration of Independence. That's right: the declaration could've included "they're conscripting our slaves" as a reason for independence.

For white slaveholders in the South, Simon Schama writes in Rough Crossings, his history of black loyalism during the Revolution, the war was "a revolution, first and foremost, mobilized to protect slavery."

Slaves also understood that their odds of liberation were better under British rule than independence. Over the course of the war, about 100,000 African slaves escaped, died, or were killed, and tens of thousands enlisted in the British army, far more than joined the rebels. "Black Americans' quest for liberty was mostly tied to fighting for the British — the side in the War for Independence that offered them freedom," historian Gary Nash writes in The Forgotten Fifth, his history of African Americans in the revolution. At the end of the war, thousands who helped the British were evacuated to freedom in Nova Scotia, Jamaica, and England.

This is not to say the British were motivated by a desire to help slaves; of course they weren't. But American slaves chose a side in the revolution, the side of the crown. They were no fools. They knew that independence meant more power for the plantation class that had enslaved them and that a British victory offered far greater prospects for freedom.

Independence was bad for Native Americans

Starting with the Proclamation of 1763, the British colonial government placed firm limits on westward settlement in the United States. It wasn't motivated by an altruistic desire to keep American Indians from being subjugated or anything; it just wanted to avoid border conflicts.

But all the same, the policy enraged American settlers, who were appalled that the British would seem to side with Indians over white men. "The British government remained willing to conceive of Native Americans as subjects of the crown, similar to colonists," Ethan Schmidt writes in Native Americans in the American Revolution. "American colonists … refused to see Indians as fellow subjects. Instead, they viewed them as obstacles in the way of their dreams of land ownership and trading wealth." This view is reflected in the Declaration of Independence, which attacks King George III for backing "merciless Indian Savages."

American independence made the proclamation void here. It's not void in Canada — indeed, there the 1763 proclamation is viewed as a fundamental document providing rights to self-government to First Nations tribes. It's mentioned explicitly in the Canadian Charter of Rights and Freedoms (Canada's Bill of Rights), which protects "any rights or freedoms that have been recognized by the Royal Proclamation of October 7, 1763" for all aboriginal people. Historian Colin Calloway writes in The Scratch of a Pen: 1763 and the Transformation of North America that the proclamation "still forms the basis for dealings between Canada's government and Canada's First Nations."

And, unsurprisingly, Canada didn't see Indian wars and removals as large and sweeping as occurred in the US. They still committed horrible, indefensible crimes. Canada, under British rule and after, brutally mistreated aboriginal people, not least through government-inflicted famines and the state's horrific seizure of children from their families so they could attend residential schools. But the country didn't experience a westward expansion as violent and deadly as that pursued by the US government and settlers. Absent the revolution, Britain probably would've moved into Indian lands. But fewer people would have died.

None of this is to minimize the extent of British and Canadian crimes against Natives. "It's a hard case to make because even though I do think Canada's treatment of Natives was better than the United States, it was still terrible," the Canadian essayist Jeet Heer tells me in an email (Heer has also written a great case against American independence). "On the plus side for Canada: there were no outright genocides like the Trail of Tears (aside from the Beothuks of Newfoundland). The population statistics are telling: 1.4 million people of aboriginal descent in Canada as against 5.2 million in the USA. Given the fact that America is far more hospitable as an environment and has 10 times the non-aboriginal population, that's telling."

Independence also enabled acquisition of territory in the West through the Louisiana Purchase and the Mexican-American War. That ensured that America's particularly rapacious brand of colonialism ensnared yet more native peoples. And while Mexico and France were no angels, what America brought was worse. Before the war, the Apache and Comanche were in frequent violent conflict with the Mexican government. But they were Mexican citizens. The US refused to make them American citizens for a century. And then, of course, it violently forced them into reservations, killing many in the process.

American Indians would have still, in all likelihood, faced violence and oppression absent American independence, just as First Nations people in Canada did. But American-scale ethnic cleansing wouldn't have occurred. And like America's slaves, American Indians knew this. Most tribes sided with the British or stayed neutral; only a small minority backed the rebels. Generally speaking, when a cause is opposed by the two most vulnerable groups in a society, it's probably a bad idea. So it is with the cause of American independence.

America would have a better system of government if we'd stuck with Britain

Honestly, I think earlier abolition alone is enough to make the case against the revolution, and it combined with less-horrible treatment of American Indians is more than enough. But it's worth taking a second to praise a less important but still significant consequence of the US sticking with Britain: we would've, in all likelihood, become a parliamentary democracy rather than a presidential one.

And parliamentary democracies are a lot, lot better than presidential ones. They're significantly less likely to collapse into dictatorship because they don't lead to irresolvable conflicts between, say, the president and the legislature. They lead to much less gridlock.

In the US, activists wanting to put a price on carbon emissions spent years trying to put together a coalition to make it happen, mobilizing sympathetic businesses and philanthropists and attempting to make bipartisan coalition — and they still failed to pass cap and trade, after millions of dollars and man hours. In the UK, the Conservative government decided it wanted a carbon tax. So there was a carbon tax, and the coal sector has taken a beating. Just like that. Passing big, necessary legislation — in this case, legislation that's literally necessary to save the planet — is a whole lot easier with parliaments than with presidential systems.

There are of course exceptions — you need only look at Theresa May’s years of struggle to put together a Brexit package that satisfies her party. But it’s notable that that fiasco began with a deviation from parliamentary government, when David Cameron decided to punt the question of leaving the European Union to the voters. It was the introduction of another unnecessary decisionmaking entity, very common in the veto point-heavy US system, that created the crisis in the first place.

This is no trivial matter. Efficient passage of legislation has huge humanitarian consequences. It makes measures of planetary importance, like carbon taxes, easier to get through; they still face political pushback, of course — Australia's tax got repealed, after all — but they can be enacted in the first place, which is far harder in the US system. And the efficiency of parliamentary systems enables larger social welfare programs that reduce inequality and improve life for poor citizens. Government spending in parliamentary countries is about 5 percent of GDP higher, after controlling for other factors, than in presidential countries. If you believe in redistribution, that's very good news indeed.

The Westminister system of parliamentary democracy also benefits from weaker upper houses. The US is saddled with a Senate that gives Wyoming the same power as California, which has more than 66 times as many people. Worse, the Senate is equal in power to the lower, more representative house. Most countries following the British system have upper houses — only New Zealand was wise enough to abolish it — but they're far, far weaker than their lower houses. The Canadian Senate and the House of Lords affect legislation only in rare cases. At most, they can hold things up a bit or force minor tweaks. They aren't capable of obstruction anywhere near the level of the US Senate.

Finally, we'd still likely be a monarchy, under the rule of Elizabeth II, and constitutional monarchy is the best system of government known to man. Generally speaking, in a parliamentary system, you need a head of state who is not the prime minister to serve as a disinterested arbiter when there are disputes about how to form a government — say, if the largest party should be allowed to form a minority government or if smaller parties should be allowed to form a coalition, to name a recent example from Canada. That head of state is usually a figurehead president elected by the parliament (Germany, Italy) or the people (Ireland, Finland), or a monarch. And monarchs are better.

Monarchs are more effective than presidents precisely because they lack any semblance of legitimacy. It would be offensive for Queen Elizabeth or her representatives in Canada, New Zealand, etc. to meddle in domestic politics. Indeed, when the governor-general of Australia did so in 1975 it set off a constitutional crisis that made it clear such behavior would not be tolerated. But figurehead presidents have some degree of democratic legitimacy and are typically former politicians. That enables a greater rate of shenanigans — like when Italian President Giorgio Napolitano schemed, successfully, to remove Silvio Berlusconi as prime minister due at least in part to German Chancellor Angela Merkel's entreaties to do so.

Napolitano is the rule, rather than the exception. Oxford political scientists Petra Schleiter and Edward Morgan-Jones have found that presidents, whether elected indirectly by parliament or directly by the people, are likelier to allow governments to change without new elections than monarchs are. In other words, they're likelier to change the government without any democratic input at all. Monarchy is, perhaps paradoxically, the more democratic option.

Watch: How America became a superpower