In the '40's and early '50's, milk came in 1 qt. glass bottles. Refrigerators were small and would only hold 2 or 3 bottles. Most families were lucky to have one car, and the man usually took that to work, leaving Mom at home with no car. Milk delivery was a big help for her.
The milk came in three varieties. Skim, homogenized, and “cream top”, which was a special bottle with a bulge at the top. This allowed the cream to rise to the bulged top with the skim milk below. The dairy provide a free special spoon. When you inserted this spoon into the cream top bottle, it blocked the narrow section between the cream and the skim. You could then pour off the cream into your cream pitcher and save the skim for your cereal.
Milk truck brakes squealed whenever they were used. I don't know why, because other truck brakes did not. When you heard the milk truck squeak to a stop on your street, you knew to get your milk from the “milk box” on your porch before it either froze or spoiled , depending on the season.
The trucks were not refrigerated, but in the Summer, they kept the milk cold with chunks of ice. On hot days you could get the driver to give you a chunk to lick and suck on. I am sure that the back of those milk trucks were just full of pro-biotics that protected us from all of those diseases that there had no vaccines available yet. I never understood how anyone could pass up on anything free that would cool you off, slake your thirst and clean your hands. I don't think I ever saw a girl get milk truck ice and I guess they had to go home to rinse their hands if they wanted to.
As refrigerators got larger and the dairies switched to waxed paper cartons (yes they came before the current plastic coated cartons), the need for milk delivery ended. No more ice for the hot and thirsty. No more “milk boxes” on the porch and doctors got rich treating allergies.