Slave States and Free States in 1860: Full Map & Count

The direct answer: in 1860, on the eve of the Civil War, the United States contained 19 free states and 15 slave states — a total of 34 states.

What “Slave State” and “Free State” Actually Meant

A free state was one where slavery and the internal slave trade were prohibited by law. A slave state was one where both remained legal. The distinction was about state law, not about whether Black people actually lived free within a state’s borders.

Two caveats complicate the labels. Small numbers of enslaved people still appeared in the census in some free states up to 1840, usually held under gradual-abolition loopholes. And the Fugitive Slave Clause of the Constitution — enforced through the Fugitive Slave Act of 1793 and the harsher Fugitive Slave Act of 1850 — meant an enslaved person did not become free simply by reaching a free state. They could be seized and returned, as the Wikipedia overview of slave and free states details.

The Full Count in 1860

By the time Abraham Lincoln was elected in November 1860, the Union had grown to 34 states. Here is how they split.

The 19 Free States

Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Ohio, Indiana, Illinois, Michigan, Wisconsin, Minnesota, Iowa, California, Oregon, and Kansas.

Kansas was the newest of these. It entered the Union in January 1861 following years of violent conflict over whether it would permit slavery — the period known as “Bleeding Kansas.” Its admission as a free state was the final straw that broke the long-standing sectional balance.

The 15 Slave States

Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Texas, Arkansas, Tennessee, Kentucky, and Missouri.

Four of these — Delaware, Maryland, Kentucky, and Missouri — would remain in the Union during the Civil War as “border states,” even though they still permitted slavery in 1860.

How the Balance Was Maintained for Decades

The 19–15 split was not accidental. For roughly four decades, from about 1812 to 1850, slave-state leaders treated it as politically essential that the number of free states never exceed the number of slave states. Because each state gets two senators regardless of population, admitting new states in matched pairs kept the Senate evenly divided.

The mechanism was straightforward: admit one free state and one slave state together. The Missouri Compromise of 1820 is the classic example — Missouri came in as a slave state while Maine came in as a free state, preserving the tie.

This pairing worked only as long as free and slave territory expanded at roughly the same pace. Once the free states’ population and territorial reach outgrew the slave states’, the arithmetic could no longer be managed — and the 1860 count shows the result.

Why the Numbers Mattered So Much

The sectional balance was never just about symbolism. It had direct constitutional consequences.

• The Senate. With 19 free states to 15 slave states, the free states held 38 Senate seats to the slave states’ 30. For the first time, the free states could potentially control the chamber outright.
• The House of Representatives. The free states had long dominated the House because apportionment follows population, and the free states’ population was growing faster. The three-fifths compromise had partially offset this for the slave states, but it was not enough.
• The Electoral College. The same population advantage gave free states more electoral votes, which was decisive in Lincoln’s 1860 victory — a win achieved with essentially no support in the slave states.
• The possibility of amendment. A free-state majority in both chambers raised the prospect that slavery could one day be restricted or abolished through ordinary constitutional means, which is precisely what slave-state leaders had spent decades preventing.

A Short Worked Example: How One Pair Kept the Peace

Take the Missouri crisis of 1819–1820. Missouri applied for statehood as a slave state, which would have given the slave states a 12–11 edge in the Senate. Northern opponents objected. The Compromise of 1820 resolved it by admitting Maine as a free state at the same time, restoring the 12–12 tie and, just as importantly, drawing a line across the Louisiana Purchase territory — slavery would be banned north of that line, with Missouri as the exception.

For thirty years the formula held. But it depended on a steady supply of paired admissions, and by the 1850s that supply was exhausted. When Kansas sought statehood, there was no free-state/slave-state pair left to trade. The balance broke, and with it the political arrangement that had kept the Union together.

What Happened Next

After fighting began in April 1861, eleven slave states seceded and formed the Confederacy. The remaining slave states that stayed in the Union became a complicated middle ground.

During the war, slavery was abolished in some of the slave states — most famously by the Emancipation Proclamation of 1863, which applied to areas in rebellion. But it took a constitutional amendment to end the institution everywhere. The Thirteenth Amendment, ratified in December 1865, abolished chattel slavery throughout the United States. At that point the legal category of “slave state” ceased to exist. You can find the text and ratification history through the National Archives.

Key Takeaways

• In 1860 the United States had 34 states: 19 free and 15 slave.
• The free states were Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Ohio, Indiana, Illinois, Michigan, Wisconsin, Minnesota, Iowa, California, Oregon, and Kansas.
• The slave states were Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Texas, Arkansas, Tennessee, Kentucky, and Missouri.
• The 19–15 edge gave free states control of the Senate (38 seats to 30) for the first time, ending the long practice of admitting states in slave–free pairs to preserve a tie.
• Kansas, admitted as a free state in January 1861 after “Bleeding Kansas,” was the last state to enter the Union before the Civil War.
• “Free state” described state law, not lived reality — the Fugitive Slave Acts meant an enslaved person did not become free by crossing into free territory.
• The split did not survive: eleven slave states seceded in 1861, and the Thirteenth Amendment abolished chattel slavery nationwide in December 1865.