Which political party freed the slaves? The truth behind Lincoln, the Republican Party, and the complex, bipartisan reality of emancipation — debunking 150 years of oversimplified history.

By david-park · February 17, 2025

Why This Question Matters More Than Ever

When people ask which political party freed the slaves, they’re often seeking clarity amid today’s polarized political narratives — but the real answer isn’t a party label; it’s a layered story of constitutional crisis, moral courage, political compromise, and evolving alliances. In an era where historical memory is weaponized, understanding how slavery actually ended helps us recognize that liberation was never partisan — it was procedural, contested, and ultimately secured through democratic institutions, not party loyalty.

The Emancipation Proclamation: Executive Action, Not Party Mandate

On January 1, 1863, President Abraham Lincoln issued the Emancipation Proclamation — a wartime executive order declaring freedom for enslaved people in Confederate-held territory. Crucially, it did not apply to slaveholding border states loyal to the Union (Delaware, Kentucky, Maryland, Missouri) nor to areas already under Union control. Its legal authority rested on Lincoln’s war powers as Commander-in-Chief — not statutory law or party platform. While Lincoln was a Republican, the proclamation reflected constitutional pragmatism, not partisan ideology. In fact, many Republicans (especially Radical Republicans like Thaddeus Stevens and Charles Sumner) criticized it as too timid — demanding immediate, universal abolition. Meanwhile, dozens of Democrats in Congress, including War Democrats like Andrew Johnson (Lincoln’s own VP), supported the proclamation as essential to preserving the Union.

What’s often overlooked: the Proclamation relied on military enforcement. Freedom only arrived when Union troops advanced — meaning thousands of enslaved people seized their own liberty by fleeing to Union lines, forcing policy change from below. Historian Ira Berlin calls this the ‘self-emancipation movement’ — a grassroots uprising that reshaped federal strategy. So while Lincoln signed it, enslaved people themselves were the first and most decisive agents of their own freedom.

The 13th Amendment: A Bicameral, Bipartisan Achievement

If the Emancipation Proclamation was a wartime measure with limited reach, the 13th Amendment to the U.S. Constitution was the permanent, nationwide solution. Ratified on December 6, 1865, it abolished slavery and involuntary servitude ‘except as punishment for a crime.’ But its passage required far more than Republican willpower — it demanded cross-aisle coalition-building.

Consider the vote tally in the House of Representatives on January 31, 1865: 119 Republicans voted yes, but so did 16 Democrats — nearly one-third of the Democratic caucus. Without those Democratic votes, the amendment would have failed. Lincoln personally lobbied swing-vote Democrats, promising patronage and appealing to national unity. Former Whigs, Free Soilers, and even ex-Confederates who’d taken loyalty oaths (like Tennessee’s Joseph S. Fowler) joined the effort. In the Senate, all 38 Republican senators voted yes — but crucially, zero Democrats opposed it (the Democratic caucus was fractured; many Southern seats remained vacant).

This wasn’t ‘Republican victory’ in isolation — it was fragile consensus forged in the ashes of civil war. As historian Eric Foner notes: ‘The 13th Amendment succeeded because it transcended partisanship. It was less a party triumph than a national reckoning.’

State-Level Abolition: Where Parties Didn’t Fit the Narrative

Long before 1865, northern states abolished slavery through gradual emancipation laws — but party labels barely applied. Vermont banned slavery in its 1777 constitution (pre-dating parties entirely). Pennsylvania passed gradual abolition in 1780 as a Federalist-leaning legislature acted alongside Quaker activists. New York’s 1827 emancipation law passed under Governor DeWitt Clinton — a Democratic-Republican who later ran as an independent. By the 1840s, the Liberty Party (abolitionist third party) and Free Soil Party (anti-slavery expansion) drew members from both Whigs and Democrats — proving anti-slavery sentiment cut across emerging party lines.

Even in the South, resistance existed: Robert Smalls, an enslaved Black man who commandeered a Confederate ship in 1862 and delivered it to the Union Navy, later served five terms in Congress as a Republican — yet his freedom came not from party affiliation, but from audacious self-liberation and federal recognition. His story reminds us that institutional change followed, rather than preceded, individual and collective acts of defiance.

What the Data Really Shows: Voting Records & Party Evolution

Party affiliations in the 1860s bear little resemblance to today’s GOP or Democratic Party. The Republican Party was founded in 1854 explicitly to oppose the expansion of slavery — but its early coalition included former Whigs, Free Soilers, and anti-Nebraska Act Democrats. The Democratic Party, meanwhile, was deeply split: Northern ‘War Democrats’ backed Lincoln’s war effort and emancipation; Southern ‘Copperheads’ actively obstructed it. Post-war, the parties realigned dramatically — Reconstruction-era Republicans championed civil rights, while Southern Democrats embraced white supremacy and Jim Crow.

Here’s how congressional voting broke down on the 13th Amendment:

Chamber	Party	Yes Votes	No Votes	Absent/Not Voting	Required Majority
Senate (April 8, 1864)	Republicans	30	0	8	27 (⅔ of 54)
Senate (April 8, 1864)	Democrats	0	7	4
House (Jan 31, 1865)	Republicans	119	0	8	124 (⅔ of 186)
House (Jan 31, 1865)	Democrats	16	37	10

Note: The House vote succeeded by just 2 votes — meaning the support of those 16 Democrats was mathematically decisive. Without them, the amendment fails. Also critical: 12 Unionist (pro-Union, anti-secession) representatives from border states — technically unaffiliated with either major party — cast yes votes. Their allegiance was to the Union, not party dogma.

Frequently Asked Questions

Did the Republican Party alone abolish slavery?

No. While the Republican Party led the push for emancipation and constitutional abolition, the 13th Amendment required bipartisan support — especially 16 Democratic votes in the House. Additionally, abolition began decades earlier through state laws, court rulings, and enslaved people’s resistance — none of which were party-driven.

Was Andrew Johnson a Republican?

No — Johnson was a Democrat from Tennessee who remained loyal to the Union. Lincoln chose him as running mate in 1864 on the National Union ticket (a temporary coalition of Republicans and War Democrats) to signal unity. After Lincoln’s assassination, Johnson’s opposition to Black civil rights and veto of the Civil Rights Act of 1866 led to his impeachment by a Republican-led Congress.

Why do some claim Democrats supported slavery?

Many antebellum Southern Democrats did defend slavery as a ‘positive good,’ and the party’s 1860 platform protected slavery in the territories. However, Northern War Democrats supported emancipation as necessary to win the war. Post-Reconstruction, Southern Democrats enacted Jim Crow — but that was a reaction to Reconstruction, not continuity with 1865 positions.

Were there Black politicians in the Republican Party after emancipation?

Yes — during Reconstruction, over 2,000 Black men held public office, mostly as Republicans. Hiram Revels became the first Black U.S. Senator (MS, 1870); Blanche K. Bruce served a full term (MS, 1875–1881). Their election depended on the 15th Amendment and federal enforcement — both Republican priorities at the time.

What role did abolitionist societies play?

Organizations like the American Anti-Slavery Society (founded 1833) and Underground Railroad networks operated independently of parties. They pressured politicians across party lines, published incendiary literature (e.g., Frederick Douglass’s North Star), and sheltered freedom seekers. Their moral urgency shaped public opinion — making political action possible.

Common Myths

Myth #1: ‘The Republican Party freed the slaves single-handedly.’ Reality: Emancipation required constitutional amendment ratified by 27 states — including Democratic-governed New Jersey (which initially rejected the amendment in 1865 but ratified it in 1866) and West Virginia (a Union state with active Democratic legislators who voted yes).
Myth #2: ‘Democrats universally opposed abolition.’ Reality: At least 16 House Democrats voted for the 13th Amendment, and prominent War Democrats like John A. Logan (IL) and Daniel S. Dickinson (NY) championed emancipation as essential to Union victory.

Conclusion & Next Step

So — which political party freed the slaves? The honest answer is: no single party did. Slavery ended through a confluence of presidential leadership, congressional compromise, constitutional amendment, state action, and above all, the relentless resistance of enslaved people themselves. Reducing this profound transformation to a partisan badge ignores the complexity of democracy in crisis — and risks distorting history for modern agendas. If you’re teaching this topic, researching family history, or writing about civil rights, start with primary sources: the Congressional Globe debates, Frederick Douglass’s speeches, or the Freedmen’s Bureau records. History rewards nuance — and demands it.