153 years ago today, Abraham Lincoln signed the Emancipation Proclamation, one of the most well known documents in American history. The proclamation ended slavery in the Confederate states and made ending slavery an explicit war goal of the North. Though it instantly freed 3 million slaves in the eyes of the federal government, it also gave the North an important  strategic advantage in the war effort against the South.

Slave states that remained in the Union were allowed to continue holding slaves, encouraging their loyalty to the Union. Slaves who abandon their southern owners would no longer be returned, which disrupted the Confederate economy. Prior to the Emancipation Proclamation, the Fugitive Slave Act of 1850 required that escaped slaves be returned to their owners under federal law. The proclamation ended federal enforcement of slavery in the South. It also raised the Union’s reputation in Great Britain, which was staunchly anti-slavery.

The Emancipation Proclamation signalled the beginning of the end of slavery in the United States. If the North won the war, slavery was very likely to end throughout the entire country. The proclamation gave the North a rhetorical, moral authority over the South. Union soldiers could claim to be fighting for the end of slavery, while the South would forever be seen as defending the institution.

Since the end of the Civil War, we’ve learned that true liberty is more than just the absence of slavery. The right to keep the fruits of one’s own labor is still under fire today. Slavery is the most egregious denial of individual liberty, but there are other forms of control that slowly and insidiously rob the individual of their personhood. Though there is still work to be done, the Emancipation Proclamation moved the United States towards a more libertarian society.