1. The First Abolition: Prior to the American Revolution, every New World colony, British or otherwise, legally sanctioned slavery, and nearly every colony counted enslaved people among its population. As late as 1770, nearly twice as many Africans were in bondage throughout the colony of New York as within Georgia, although slaves were a much larger percentage of Georgia’s population. Yet the Revolution’s liberating spirit brought about outright abolition or gradual emancipation in all northern states by 1804. ... In 1786, the Confederation Congress also prohibited the extension of slavery into the Northwest Territory.
There is a tendency to minimize this first emancipation because slavery had been less economically entrenched in the northern colonies than in the southern colonies and because in many northern states slavery was eliminated gradually. But emancipation had to start somewhere. ... Even in southern colonies, the Revolution’s assault on human bondage made some inroads. Several southern states banned the importation of slaves and relaxed their nearly universal restrictions on masters voluntarily freeing their own slaves. Through resulting manumissions, 10,000 Virginia slaves were freed, more than were freed in Massachusetts by judicial decree. ...
2. Separation of Church and State: ... Although the British colonies prior to the Revolution already practiced a relatively high degree of religious toleration, only four of thirteen colonies had no established, tax-supported church: Rhode Island, New Jersey, Pennsylvania, and Delaware. As a result of the Revolution, the five other southern states and New York disestablished the Anglican Church. With the adoption of the Constitution and then the First Amendment, the United States become the first country to separate church and state at the national level. Several of the New England states, however, retained their established Congregational Church, with Massachusetts becoming the last to fully abolish tax support as late as 1833. In our modern secular age, it is too easy to take these accomplishments for granted, but they were unprecedented.
3. Republican Governments: As a result of the Revolution, nearly all of the former colonies adopted written state constitutions setting up republican governments with limitations on state power embodied in bills of rights. ... The new state constitutions often extended the franchise, with Vermont being again the first jurisdiction to adopt universal male suffrage with no property qualifications and explicitly without regard to color. Going along with this was a reform of penal codes throughout the former colonies, making them less severe, and eliminating such brutal physical punishments as ear-cropping and branding, all still widely practiced in Britain. ...
4. Extinguishing the Remnants of Feudalism and Aristocracy: ... All the new states abolished primogeniture (the sole right of inheritance to the firstborn son) and entail (a prohibition of the sale, break up, or transfer to outside the family of an estate) where they existed, either by statute or by constitutional provisions. Doing so not only eliminated economically inefficient feudal encumbrances on land titles but also was a blow against hereditary privilege and the patriarchal family, because it undermined traditional patterns of inheritance and facilitated the rights of daughters and widows to possess property. ...
The U.S. Constitution’s prohibition on titles of nobility may seem trivial and quaint to modern eyes. But such titles, still prevalent throughout the Old World, always involved enormous legal privileges. This provision is, therefore, a manifestation of the extent to which the Revolution witnessed a decline in deference throughout society. ... White employees no longer referred to their employers as “master” or “mistress” but adopted the less servile Dutch word “boss.” Men generally began using the designation of “Mr.,” traditionally confined to the gentry. ... In the Revolution’s aftermath, indentured servitude for immigrants withered away, and most states eliminated legal sanctions enforcing long-term labor contracts for residents, thus giving birth to the modern system of free labor, where most workers (outside of the military) can quit at will.There's much more of interest in the essay, including discussion of how, in the years before the US Revolution, "British hard-liners intended to fasten on North America an imperial regime in many respects similar if not identical to British rule in India."
Another interesting speculation is that if Britain had held on to the American colonies, then Britain might not have been able to muster a political majority to abolish slavery in 1833. Britain's move to abolish slavery at that time was able to overcome the opposition from British sugar planters in the West Indies. Hummel speculates: "If American cotton, tobacco, rice, and sugar planters had still been under British rule, they inevitably would have allied with West Indian sugar planters, creating a far more powerful pro-slavery lobby. ... Thus it is likely that, without U.S. independence, slavery would have persisted in both North America and the West Indies after 1834 and, indeed, possibly after 1865."