>Lockdowns were not unique to Alghero. "In Florence, for example, they imposed a total quarantine of the city in the spring of 1631," says John Henderson, a professor of Italian Renaissance history at Birkbeck, University of London. And just as today, rule-breaking was common.
>"Over the year from the summer of 1630 to the summer of 1631, I found something like about 550 different cases that people were prosecuted for, for various infringements of the public health regulations," says Henderson. For most of that time, the city wasn't in full lockdown, but people were expected to self-isolate for 40 days if a member of their household was suspected of having the plague, and taken to hospital. This is where the word "quarantine" comes from – "quaranta giorni" means "40 days" in Italian.
Lockdowns like this have continued to be a part in public health approaches to infectious disease around the world.
The fact that a majority of Americans, convinced of their exceptionalism in every way, would oppose such an approach doesn't mean that it is inherently impossible or nonfunctional.
If Trump had demanded a full lockdown in March like you're suggesting, it would have been opposed by everyone.