The American surly does philosophy on their own unique way, different from what cames down from the scriptures of antiquaty and of traditional approaches in both Europa and Asia.
It's kind of a suprisingly difficult question how to characterise the difference. I believe part of the difference stems from the fact that America has been a middle-class society right from the beginning. There has just never been a aristocratic or cleric upper class that shaped philosophical thinking in a form according to their taste.
However, this middle-classness comes with a price. Too often, the American philosophical mind gives victory to the common-sense position effortlessly. As a result of this, some consideration are boring. Other are just perplexing, e.g. this strange view that »moral intuition« can sattle ethical question, just like a experiment could answer scientific ones.