What did the American Revolution really achieve? A historian's view on the new republic, slavery and global impact

Days before the 250th anniversary of the Declaration of Independence is to be marked, HistoryExtra has produced a podcast that resists easy celebration and asks a more basic question: what did the American Revolution actually achieve? Elinor Evans speaks with University College London historian Adam IP Smith, drawing out a nuanced picture that runs from military strategy to moral compromise.

Smith's starting point is military: "The Revolution was nearly lost twice before it was won." By the late summer of 1776, with Washington's army retreating from New York and then into Pennsylvania, American independence looked unlikely militarily. "Without the winter victories at Trenton and Princeton," Smith says, "Congress would have been at the negotiating table by February 1777 and would in all likelihood have accepted Britain's terms."

The attritional hardship of the campaigns is Smith's second theme. The winter at Valley Forge — Pennsylvania, 1777-78 — cost Washington's army about a third of its strength to illness and starvation. The British side meanwhile buckled under the logistical weight of the Atlantic crossing: each shipload of troops took six to eight weeks from England, resupply was patchy, no local lease arrangements existed. The metaphor for victory in this war is not the clash of regular armies but the question of which side could outlast the other.

The third theme is foreign support. The 1781 victory at Yorktown was not just an American achievement but a French one: 5,500 troops under Comte de Rochambeau and 28 warships under Admiral de Grasse made the encirclement possible. "American independence was won at Versailles," Smith says. The Netherlands and Spain provided covert support too. It is a fact American national myth-history would later soften, but military historians do not dispute it.

The Revolution's global impact is the fourth strand. Within three years, the Revolution had laid much of the ideological ground for the French Revolution of 1789. Lafayette's draft of the Declaration of the Rights of Man, which would inform the crowd that took the Bastille, was directly informed by the American Declaration. The Revolution also became the reference point for the 1791 Haitian Revolution, the 1810-20 Latin American wars of independence, and the liberal uprisings across 19th-century Europe.

But the moral problem stayed. The Revolution used the language of equality without abolishing slavery. As Smith puts it: "Of the 56 men who signed the line 'all men are created equal', 41 owned enslaved people. That was not understood as a moral inconsistency; it was understood as logical — the word 'men' had a deliberately narrow application." Abolition would wait another 87 years and a four-year civil war.

Another dimension the Revolution did not deliver: votes for women. Abigail Adams's famous March 1776 letter to her husband John Adams urged him to "remember the ladies". John Adams replied, after part of her letter had reached print, that a women's-rights demand "would be laughed at and derail the Revolution". The vote for women in the United States arrived in 1920 — 144 years after the Declaration.

For Native American peoples the Revolution was a direct catastrophe. "Britain had issued the 1763 Royal Proclamation forbidding European settlement west of the Appalachians," Smith explains. "For the 13 colonies that was a constraint; for the Mohawk, the Onondaga, the Cherokee, the Iroquois Confederacy and others, it was a protection. The Revolution removed that protection." Native land in the Ohio Valley was systematically encroached upon in the early 1790s.

Economically, the Revolution shifted the United States away from the mercantilist mindset of imperial Britain and toward a more liberal trading ideal. The US Constitution federalised tariffs but did not enshrine free trade as a fundamental right. Through the 19th century, the rapidly expanding consumer base and waves of immigration meant the American economy outgrew Britain's imperial-model economy; by 1900, US GDP was double Britain's.

Smith's closing assessment: "What the American Revolution achieved is summarisable in a single sentence: the first modern application of the principle of government by the consent of the governed. What it failed to achieve — abolition, women's equality, Native rights, economic justice — became the agenda of the next 250 years. Anniversaries of this kind are unavoidable; their scholarly value depends on being able to see both what was achieved and what was not." The 250th anniversary is a milestone that compels both readings at once — neither pure celebration nor pure critique, but the two together.