Please note that in my previous post I had noted that the feds have no power to regulate intrastate medical quarantine policy. I need to clarify that the feds have no power to quarantine US citizens with respect to intrastate issues, such as ordering US citizens to stay home on election day. If it becomes necessary to do so, then that is a state's prerogative.
Regarding federal quarantine laws as they concern the National Quarantine Act of 1878, I suspect that the Marine Hospital Service in New Orleans that was used to check foreigners from the south who were fleeing a yellow fever epidemic is an example of the federal entities listed in the Constitution’s Clause 17 of Section 8 of Article I. Such entities, military hospitals in this case, are under the exclusive control of Congress, the National Quarantine Act constitutionally justified in such a case.
Regarding the later history of federal quarantine laws through the early 20th century, the states were wrong to simply administratively transfer control of quarantine stations to the feds without appropriately delegating such power to the feds with a constitutional amendment. It’s good evidence that the nation was forgetting about the federal government’s constitutionally limited powers by that time.
In fact, note that the 16th, 17th, 18th and 19th Amendments which had been passed by 1920 are examples of the influence of the anti-Constitution, one central government Progressive Movement, the quarantine system fully nationalized by 1921.