The federal government doesn't have the authority to lockdown the whole country, only the national and state borders. To lockdown the whole country all 50 states would need to individually issue orders, which is unlikely.

I suspect the governors of some rural states are likely to issue weaker social distancing orders, minimizing the economic impact but still benefiting from national economic relief legislation the same as states more severely effected.

The federal government might just get such authority from Congress, if things keep going the way they are.

There would certainly be a lawsuit claiming that it's unconstitutional. It might even win... eventually. You know, back when SCOTUS is in proper session, and it's all kinda moot.

You implore people not to encourage panic in one breath then make the absurd suggestion that the US is going to impose "mandatory lockdown to the whole country soon".