Reenacting at Gettysburg before reenactors

[Fire Marshal Bill]

Looking for a bit of help, and wondering if anyone here may have some info to help me out. Back in the early 1900s or teens, I once saw that the US military was traveling to the various Civil War battlefields and were giving demonstrations as to how that battle would have been fought with “modern” equipment, technology and tactics. Does anyone have information as the when or even if they ever did this at Gettysburg?

I do believe they did, but I can't find any information.

Thanks for any help