Mark Twain - Travel is fatal to prejudice.

Twain also wrote often about meeting annoying US tourists on his travels and going out of his way to avoid them. For example in "A Tramp Abroad", after describing a particular annoying interaction with one he writes:

And away he went. He went uninjured, too—I had the murderous impulse to harpoon him in the back with my alpenstock, but as I raised the weapon the disposition left me; I found I hadn’t the heart to kill him, he was such a joyous, innocent, good-natured numbskull.