Sarnella I can't stop now, I've too much invested in the argument ... 😂
Google Open Championship and results are 95% that, Open Championship. Google British Open Championship and the only references you'll get is American media. Even the PGA Tour website calls it the Open Championship.
Yours was the first PGA Championship and is always just that, even here, the PGA, rarely (if ever) USPGA.
Other countries have their PGA Championships, for example there are English, Scottish and British PGA Championships (Bristish started in 1955) but they're called exactly that (although the current incarnation is the BMW PGA Championship for sponsorship reasons).