Growing up as a kid in the '60's we had milk delivered to our home twice a week. Mr. Kelloway, in his blue and white pin striped overalls and jaunty cap, would arrive in his panel truck. He would gather up bottles of milk and cream, stow then in a metal carrying rack, then swing up the pathway on his impossibly long legs. If were not home, he would tuck those bottles into an aluminum cooler made specifically for this purpose that sat by the back door. We used to hide the spare house key under there, too.
The milk was, of course, pasteurized. Pasteurization of milk, (the process of heating it to 161.6 degrees for 15 seconds) became mandatory in most states by the 1930's. The topic of pasteurized vs. raw milk is one that is hotly debated. Many people want the right to choose to use and enjoy raw milk, believing that the pasteurization process kills many of the valuable nutrients in milk and changes the chemical composition of it in undesirable ways.
But when I waver I think about how humans have prized milk from goats, cows, yaks, camels, sheep, reindeer and even horses for as long as the earliest records have been kept. Early human artifacts have traces of milk residue... humans have been drinking raw milk for 30,000 years.