Before the 1965 Immigration Act kicked in and we started getting illegals by the millions, this was yet another job that was done by Americans.
Like dishwasher, ditch digger, laborer, it was a job that was easy to get and easy to do, the kind of thing that is now replaced with welfare, and that teens are kept out of almost entirely.
“Easy to do”? Spoken like a man who has never been a dishwasher or a ditch digger.