From which culture did our North American meal progression (soup/salad/appetizer + meal + dessert) come from?
The basic principle of serving a dish at a time is called Russian Service by the French, who started using it in the early 1800s.  The particular order of the dishes has changed with the times and with theories of how meals should be served. The book Arranging the Meal by Flandrin describes the history of these changing fashions.

There has been a debate since classic Greek times of when to have, or even whether to have, a salad course.  The Greeks suggested eating after the meal to help with the ensuing drinking.  The British were having it before the meal in the 1600s.  By the 1800s French meals served à la russe placed the salad close to the end of the meal, a tradition kept up to today.  I remember reading that the starter salad, common in the US, is a simplified antipasto, but have not been able to find the reference, so for now it is just a guess.