I was feeling bad about this until I saw that over on his science fiction and fantasy books news and reviews blog, Grasping for the Wind, John Ottinger III shared his thoughts on this topic in a July 4th essay entitled, 12 Science Fiction and Fantasy Novels and Stories of Americana:
"Today is the Fourth of July, and in the United States, we celebrate our Independence Day with fireworks, tributes to our men and women in uniform, and a hot dogs and hamburgers on the grill. It is a day to be happy that, even with its faults, we live in one of the freest countries on Earth. In commemoration of that fact, I’d like to give you a non-comprehensive list of X science fiction and fantasy books and stories that are distinctly American in flavor or content. "The list that follows ranges from Brit Neil Gaiman's American Gods (one of my all-time favs) to Stephen King, Ray Bradbury, Orson Scott Card, and even Jim Butcher.
Not only was this an interesting essay as it pertained to the discussion I was hosting, but it also serves as a nice intro to "American" science fiction and fantasy.