I'm not sure how to answer a question about how often something doesn't happen. I guess I only know for sure what I know personally -
http://www.ogt.org/regional_divisions/lincoln.cfm
(That's me with my arms folded standing behind the guy with the red Nebraska sweatshirt. I'm basically in charge of staying out of the way, but I do some publicity related stuff.)
Orphan Grain Train relief supplies/efforts are split about 50/50 between North America and the rest of the world.
Don't get me started on OGT. I'd talk your ear off.
To be fair, when it comes to donations made my private citizens, America is the most charitable nation on earth, even when it comes to donating around the world, and I'm not talking dollar amounts, I'm talking as compared per capita.
Yes America is taxed a lot less and lots of other European countries, per capita, beat us because of taxed charity, but, still, you see the point here.
Even, so, even if we are the most patriotic nation yet still the most charitable nation, my point is not to say that there are not very compassionate and patriotic people in the same soul. It is to say, that, with patriotism, we still do not view people of other countries as equals and we do not feel the same sense of duty to help poor people in, for example, Africa, as we do in, say, South Carolina.
I'm not saying that is an impractical attitude.