South Korea has not done large scale population quarantines, however, they have done massive FREE testing for the virus to the populace, in fact I'm sure most of us have seen the drive thru testing sites S. Korea has put up to make it as convenient as possible. Within hours people know the results. They have done over 200,000 tests and have set up a nationwide education and information online network to the public regarding the virus. This is a Western-style Government that has a focus coordinated effort.
Population-wise, the South Korean 200,000+ tests would be the equivalent of over a million Americans tested for the virus.
The American "count" of testing so far? 3,000.
Numbers don't lie.