I didn’t see this topic addressed before (or my search filter was inadequate), but how/when did salads get transferred from breakfast in Middle East, or mid meal in Europe to our starter course or whole meal in US?
Salads can be premade and ready to serve while the main entree is being prepared. Gives the guest something to do besides eating bread while they are waiting for the amin course.
In other words, it’s first because of restaurants. At home, I always eat mine last. It cleanses the palate (if it isn’t too heavily infused with thick gooey salad dressing).
Salads with protein in them that can serve as a meal have been around for a while, I think, in various cuisines, at least in Europe. The popularity of these salads doesn’t seem to come from the same source as having dinner salads first.
but they don’t do that in Europe–that’s why I’m asking why us?
Growing up, it was always served with the main meal, and I continue to do so, as well. And it’s kind of for the reason you mention: I like it as a palate cleanser in between bites of other things on my plate. I never understand the salad-as-a-course-unto-itself thing myself. It’s just always seemed to make more sense with something else.
My middle school French teacher told us that in France the salad is typically eaten last, because in France people usually drink wine with their meal, and the vinegary dressing would ruin the taste of the wine if the salad were eaten first.
Surely you may have observed that if something is done a ceratin way in Europe that is reason enough for true Americans to do it differently. 
silly me, what was I thinking?? It’s not 1780 anymore when we tried to adopt everything east of us. 
Of course it depends on the kind of salad. A vinegary green salad is hardly the same thing as a chicken Caesar salad with bacon, anchovies, bread crumbs, Parmesan cheese, sliced chicken breast, and – when I make it – cherry tomatoes! That’s not a “course” , it’s a meal!
Yes. I’m referring to green salads that come as a first course, not “meal salads.”
Better than the ‘Aspic Salate’ which I see often as a classical starter, perusing old menus.
ELL, I don’t know. I throw my hands up, at a culture, that turned classical Savory, Meaty Entree Aspic/Jello into the Classic, Sweet and Fruity, Dessert Jello/Aspic, within a century.