I'm merging a bunch of feature classes (400) and trying to understand the Field Map settings. I need to map multiple input fields onto one output field, but I can't figure out how to do that (it looks like I have to do it for each feature class individually, which can't be right). I've read the ESRI help page, but it just didn't go into enough detail for me. If some kind soul could step me through the process, I would appreciate it. Or if there's an ESRI tutorial that would help, I'd be grateful for the title.