[C19fan]

I noticed an article describing towed artillery via steam tractor or even steam powered self-propelled artillery.

That is the stuff of steampunk:

https://www.youtube.com/watch?v=e2oRo7eb0tQ

[BroJoeK]

Even as we speak, there's a North Carolinian living in Indianapolis, Indiana, working on a machine that sounds remarkably like the ones described here.
His name is Richard G. Gatling (not to be confused with the Gatlin Brothers!)

His invention will look something like this:

For reasons not well understood, Gatling's machine will only be occasionally used and will not much effect this war's outcome.