Surely they are taught about Henry VIII? Or do they just pretend that before America there was nothing?
Same for Serbia.
If you drive ten hours east of El Paso, you're still in Texas. It would be ridiculous and inefficient to teach Americans about Czech culture and history. If they're interested about it, they can read it.
By your logic most Texans would know nothing about anywhere more than a day's drive away.
Tudor history explains a lot about power and politics, the wives names aren't important but the lessons are.
Of course you can't teach youngsters about every country in Europe but I assume they learn about the Greek and Roman civilisations, and they could learn a hell of a lot about the human struggle from a look at the history of the Czech Republic or any other central European state.
Henry the Eighth
To six wives he was wedded.
Two divorced, two died,
One survived, one beheaded.
I suspect people either miss Texas itself (not remembering the Republic of Texas) or France (which I associate with northern North America much more).
As a Texan it was easy for me, but I could see how it might be hard to get all 6 for anyone who never studied Texas history. People familiar with American history should be able to figure out most of them though. Spain, Mexico, the Confederacy, and USA seem pretty obvious.
Divorced, beheaded, survived
The longest river is Murray/Darling
SA as an alternative for South Australia
WA as an alternative for Western Australia