Here's how I created a different look and feel for each "era":
1) I made a table of my desired effects vs. the eras I wanted to create 2) I selected all of the "old" effects for the earliest era (1890s) and made it Sepia, which goes well with The Entertainer by Scott Joplin, the soundtrack. I also sped up the playback to x4 for the very beginning to simulate the low frames-per-second rate of cameras from that time. 3) For each successive "era" I removed an effect or two, and adjusted the speed accordingly, until I had no effects and normal playback speed for "Today".
And that's about it. Pretty simple concept I think, but I'd like to re-do it, now that I have a better idea of how to do it.