http://www.greenmedinfo.com/blog/foreskin-why-it-such-secret-north-america

The male prepuce, or foreskin, is a highly mobile and extraordinarily sensitive double fold of tissue that is the end of the penis.  Why do Americans go out of their way to remove this part of human anatomy, when the rest of the world does not?

• The foreskin (or prepuce) is a man’s most sensitive erogenous zone, more well-developed in humans than in other species of mammal. It has unique sexual functions (more on that later), which circumcision effectively destroys — and this is intentional:
• Although foreskin-chopping was once a purely religious or cultural practice, it was introduced to American medicine in the late 1800s, as a ‘cure-all’, thanks to the trend of pathologizing (treating as illness) normal human sexuality and healthy genitalia.