It seems like the earliest practical steam engine was the Newcomen Engine which wikipedia dates to 1712. It was extremely inefficient so it was pretty much used

It seems like the earliest practical steam engine was the Newcomen Engine which wikipedia dates to 1712. It was extremely inefficient so it was pretty much used only at coal mines to pump water out. That water had to go somewhere and formed a canal system in England that helped take the coal to market. I think the problem with trying to find the cause of or the source of a phenomenon like the Industrial Revolution is that it's obviously multi-causal. And the inter-related bootstrap process is fascinating.