The Federal tax rate is Federal- it won't matter where you live. However each state can have it's own tax rate.

So you say the federal tax amount is fixed where ever you live and only the State tax you owe would differ depending on where you live?

Federal taxes are just that...Federal.  Are you just moving to the USA?

Adding to TurboTaxGilbertC's correct response, you may see a difference if and only if you choose itemized  deduction with state taxes withheld. But this effect is not being caused by the federal taxes but by  taxable income being reduced  due to state tax.