> At the time of the American Revolution, the British public has started raising its voice against slavery.

True. But keep in mind that Britain didn't abolish slavery in its colonies until 57 years after the American Revolution. The idea that this was a "primary" concern back in 1776 is contrived.

> At the same time, slavery was the backbone of the future US economy

That is wildly overstated, see below.

> and many of the US founding fathers were slaveholders. I think it's very valuable to know these facts, and the 1619 project does a good job of pointing them out.

True, and agreed.

> Whether the perpetuation of slavery was "a primary reason" for the American Revolution or not is IMHO of secondary importance in that context.

If it was presented as an overlooked thread of narrative about the founding, that would be one thing. But the premise behind the lead essay, and calling it the "1619 project" is that protecting slavery was "one primary reason" for the revolution. Also, it's a critical distinction. My home country declared independence in 1971. Yes, "some" people were motivated by self-interest. But the "primary reason" was because we were being oppressed by a far-away Pakistan.

> As an aside, I think the reason why the 1619 project is being attacked so hard is not because of its supposed sloppiness but because it puts a spotlight on the role of slavery in US history, and apparently that's something that many people cannot accept.

Slavery and Indian removal featured prominently in history class even when I was a kid in Virginia in the 1990s. There is a lot more we could teach--we tend to act like slavery just ended with Lincoln, and give short shrift to the end of Reconstruction, Jim Crow, etc. But the reason 1619 Project is getting so much push back is that, in Zinn-esque fashion, it uses history as a pretext to attack the constitution and capitalism.

> I think you're setting up a straw man here. The economics part establishes the role of slavery in the early US economy, and it does a good job of doing that.

Not really. First, the essay relies heavily on a work by Ed Baptist, who is neither an accountant nor an economist and makes numerous grave errors where he double- and triple- counts the contribution of slavery to the economy: http://bradleyahansen.blogspot.com/2019/09/a-guide-to-econom...

http://bradleyahansen.blogspot.com/2016/12/capitalism-and-sl... ("Ultimately, the value of cotton production was equal to about 6% of GDP.").

> One fascinating bit that I found there is that British financial markets traded bonds backed by slaves as collateral. As a consequence, the dollar value of slavery can be easily established... So at the height of slavery, the combined value of enslaved workers exceeded that of all the railroads and all the factories in the nation.

Yes, it is interesting, but ask yourself--why is it presented this way, rather than as a percentage of GDP, as above? The reason is because in what was still a pre-industrial economy, the value of "all the railroads and all the factories in the nation" wasn't very much compared to the whole economy. A free person working on a farm is part of the economy, but isn't a value-producing asset. When most of the economy is self-sustaining farmers, looking at the value of capital assets doesn't tell you much about how important something is to the economy as a whole.

If slavery had been so economically important, ending it should have at least temporarily resulted in an economic catastrophe. But you can't even see on the chart of GDP-per-capita when the U.S. and the U.K. ended slavery. Not even a blip: https://fee.org/media/35711/gdp-per-capita.png. Destroying what was supposedly half the country's "capital stock" didn't result in economic collapse because that was always a legal and financial fiction. It was labor the whole time, and the proper comparison would be to look at the output of free versus non-free labor.

In fact, if you look at the data, America got dramatically richer when it ended slavery--as economic theory would predict: https://www.econlib.org/archives/2014/09/ending_slavery.html