I have focused on different aspects in different articles. I have in fact written about the impact of slavery on the US economy: https://erik-engheim.medium.com/did-slavery-benefit-the-us-economy-925868999fe4

It was not that I didn't think it was important but that I wanted to focus specifically on the "hard work" mythology. The thing is that people worked hard all over the world. But hard work alone don't get you far unless there resources to exploit.

Europe could in principle have brought in slaves as well, but it would not have offered any economic advantage as there was no shortage of labour in Europe and there was no climate for growing the cash crops like cotton, tobacco and sugar which usually attracted slavery. We see even in the US slaves were rarely used in food production as that was not economical. It was all about the cash crops.

Capitalism definitely have many aspects helping economic growth but I wanted to also emphasize that the "wonders of capitalism" is exaggerated. In fact I think too much capitalism easily retards progress. There are many positive and almost "socialist" aspects of US economic history which helped it prosper such as sharing land with citizens (obviously at the expensive of native Americans) and protectionism to help grow American industry in its infancy.