It seems I've been absent from the guild for far too long, but now I must return and beg of your combined wisdom...

I've been working on a game for the better part of a decade and am now approaching it with renewed vigor. (And now I see the guild has undertaken a worldbuilding project of its own, if only I could find this many dedicated souls to help bring my world to life, but I digress...) The premise of my game is somewhat involved but in many ways centers around Humans living on another planet and having to start over with limited resources. There are a number of incidents/situations in this setting that present additional obstables as well.

Anyway, I'm feeling ambitious regarding the detail and realism of the game world and am trying to determine a rough analog from Earth history to where Human civilization would be in my world. So I ask this question:

What key resources/advancements/technologies were critical to various time periods in Earth history from the 14th through the 19th centuries?
I'm thinking more in terms of 25-50 year periods. It may help to think about what, if taken away, would result in a society slipping backward in terms of progress.

By the way if you're interested, the name of my game is Proteus. It takes place on the world of Ortellum and details are available at base113.com.