My two cents....
 
I am for 'historical correctness'.  It is not PC when you say to
someone from our country that Canadians, Mexicans, Guatemalans are
"Americans" and that when you go abroad and find people are upset
at you or question you further and find out you are from "the States"
and -think- America means the US when in fact it doesn't, that the people
abroad are wrong when in fact you are.  'Historical Correctness' which
I believe pc has its roots in, trys to correct for sloppy thinking
and amorphorous assumptions....