I've been going through my vintage cookbooks and to my surprise, there are few recipes for summer squash in my 1917 and 1927 editions of the Fannie Farmer Cookbook. I suppose early twentieth century cooks just knew how to prepare the produce out of their home gardens. Most of the recipes are for fried, boiled or baked squash with little more than salt and pepper, sometimes a dash of white sugar.
I did find an interesting recipe for "South American Zucchini" in the 1944 edition of The Good Housekeeping Cookbook-
2 slices bacon, diced
3 tbsp. minced onion
1/3 c. minced green pepper
1 8oz. can tomato sauce
1/2 tsp. "bottled thick meat sauce"
1 tsp. granulated sugar
1/2 tsp. salt
1/4 tsp. pepper
Obviously the tastes back then didn't like much seasoning. That's a pretty small measure of salt and pepper for 2 lbs. of zucchini. I suppose the "bottled meat sauce" was something along the lines of A-1 Steak Sauce, but a 1/2 tsp. of the stuff would barely be noticeable. Maybe they called for meat sauce for the tangy element.