Is it Legal to Quarantine People?

With the Coronavirus scare, governments are requesting citizens to restrict travel, to close businesses, and even to quarantine themselves. Is this legal? After all, American citizens have the fundamental right to travel and work a lawful profession among many rights (you may want to read my book Defending Freedom of Contact). And I believe these rights are protected by the Ninth Amendment and the Privileges and Immunities clause of the Fourteenth Amendment of the constitution. Since the government is only requesting citizens to cooperate and are not forcing them to comply with such measures, I believe it is legal. However, if and when the government makes these regulations mandatory that may be seen as a violation of Citizen rights and should be illegal. But what people need to remember is that the government can breach our fundamental rights if and only if there is a compelling reason such as protecting the safety and welfare of citizens. One can view Coronavirus as a good example of where the government can restrict the rights of the many to protect the rights of the few. For instance, citizens have the fundamental right to pursue health (this is not healthcare) and they have a fundamental right to life. This is the purpose of government, they are not tasked with creating rights, but they are tasked with protecting the rights of all citizens equally. An asymptomatic person who inflicts illness on others is a violation of their rights. So, temporarily restricting the rights of many to protect the rights of a few persons is perfectly legal. At least that is my constitutional view of the situation.