My intent with the document I've created in Adobe Illustrator was to save one as an original and one as a copy with a few different characteristics. Accidentally, I saved both with the changed characteristics. How can I revert one back to the original?
The Revert function in Illustrator takes you back to your last Save.
If you do regular back-ups or use backup software, you'll have to go back to that.
If that's not an option, then you'll have to re-do the work.
If you've closed the file then you can't. Otherwise you can try to Undo (Ctrl+Z ) until it is at the point you want, then Save it how you originally intended to. There is no
You could also
In either case you have to either work back to get to your Original, or Revert to the original and redo the changes you had wanted to save in the Copy.