As far as I can tell, the Orange Blossom is what would be known in modern parlance as a Gin n' Juice. According to Dale, David A. Embury refers to this cocktail as "the spawn of the Prohibition toad." Embury's recipe consists of gin, orange juice and simple syrup in a ratio of 2:1:1/2. I don't have Embury's volume so I do not know what else he had to say about this drink.

There's really not much going on in this drink except... orange.

Dale's version of the Orange Blossom subs Cointreau for the simple syrup and tones down the gin from Embury's version.

The 1946 Old Mr. Boston recipe consists of equal parts orange juice and gin with a pinch of powdered sugar; the recipe in Barflies & Cocktails (1927) is a straight up Gin & Juice. My personal favorite can be found in Esquire Drinks (1949), in the section titled, "Something for the Girls." It is the classic gin and juice with the addition of sweet vermouth--the conception of what the girls like has changed somewhat from those times to the present.