"Slavery would have died without the war"

Someone said, "The War could not have been about slavery because slavery was already dying and would have done so without the War."

Where This Comes Up

There are a few schools of thought as to why the Founding Fathers didn't include anything in the
Constitution about slavery. One is that they thought it was going to disappear without any interference.

When This Started

The earliest incident I can find of someone claiming that slavery was dying in the South in the mid-1800s is the 1960s. Most references I have seen about the theory are from the 21st century.

What Part is True

In 1787 when the Constitution was written, the Founding Fathers probably believed slavery was dying out.

Then in 1793, Eli Whitney invented the cotton gin.

Why It's Complicated

• Slavery was typically outlawed where it wasn't profitable. Put another way, slavery was only legally allowed where it made a profit. 
• Removing seeds from cotton was time consuming enough that it wasn't a very profitable crop. The cotton gin made that process about 25 times faster.  As a result, cotton production doubled every decade after 1800. Suddenly, you could separate the cotton faster than the current labor force could pick it.
• The response to that was the increase the size of the labor force. In the South, the growth in population of enslaved people outpaced that of free people and by 1860, the majority of people living in South Carolina and Mississippi were enslaved.
• By 1850, about 75% of the world's cotton was coming from the American South. The South's economy was completely dependent on cotton and the people who picked it.
• That's to say nothing of the economic value of enslaved people themselves. Most estimates put the value human chattel at around $3 billion dollars in 1861. That is raw dollars and is not adjusted for inflation.
• Confederate leaders wanted to expand slavery to the territories (and eventually Cuba). There was never any talk of reducing its footprint.

Who Talked About It

"The prevailing ideas entertained by him [Thomas Jefferson] and most of the leading statesmen at the time of the formation of the old constitution, were that the enslavement of the African was in violation of the laws of nature; that it was wrong in principle, socially, morally, and politically. It was an evil they knew not well how to deal with, but the general opinion of the men of that day was that, somehow or other in the order of Providence, the institution would be evanescent and pass away. This idea, though not incorporated in the constitution, was the prevailing idea at that time. The constitution, it is true, secured every essential guarantee to the institution while it should last, and hence no argument can be justly urged against the constitutional guarantees thus secured, because of the common sentiment of the day. Those ideas, however, were fundamentally wrong."

Alexander Stephens, "The Cornerstone Speech," March 1861

Click Here to explore a map that shows the expansion of slavery from 1790-1860 from Smithsonian Magazine.