It started with Denmark in 1892, and all countries soon had it after the end of WWII
Not that you asked, but I’d like to add that Canada had enabled UNIVERSAL healthcare for all, without a copay, with a universal health care law tabled in 1967.
Doctors tried to strike but soon realized that their lives and real incomes were better under national law. (Each province runs its own system.)
Source: Quora
Author: Bengt Lindvall
Retired Engineer and sales guy. Worked in many countries.