The Public Health Act of 1944 clearly established the authority of the federal government to quarantine “any individual reasonably believed to be infected with a communicable disease in a qualifying stage and…if found to be infected, may be detained for such time and in such manner as may be reasonably necessary”. Executive Orders 13295, 13375, and 13674 (issued by Presidents George W. Bush and Barack Obama) define the diseases for which the president may order quarantines on his or her own authority as
- cholera
- diphtheria
- infectious tuberculosis
- plague
- smallpox
- yellow fever
- viral hemorrhagic fevers (Lassa, Marburg, Ebola, Crimean-Congo, South American, and others not yet isolated or named)
- severe acute respiratory syndromes (SARS)
- influenza, from a novel or re-emergent source.
To the best of my knowledge these executive orders have never been challenged in court.
In addition that the states have authority to order quarantines is without question unless the state constitution expressly prohibits it. Illinois’s constitution does not contain such a prohibition.
I wouldn’t try that in the US.
Not all that long ago quarantines were commonplace in the United States. They largely became obsolete with the advent of antibiotics and vaccines. But the laws and the precedents are still on the books.
A big difference is that we are a much, much more litigious society than we used to be.