The USA is not a Commonwealth country - they formally lost that membership when they declared independence (and informally when they dumped a shipment of tea into a harbour).

If you are going to get specific about history like that, then we formally lost that membership with the Treaty of Paris, which ended the Revolutionary War, not the Declaration of Independence, which formalized why we started fighting it.

In the United States, the Employee Polygraph Protection act includes blanket exemptions for federal, state, and local governmental agencies, as well as exemptions for security services (such as guards who transport cash) and for those who handle or transport drugs.

And many states prohibit polygraphs for all private-sector employers.

That's because mi5 and 6 in the 50' thought it was a load of hokum and had a lot of influence with the commonwealth nations.