What makes American poetry American?

Cate Marvin (among others) answers the question for the Poetry Society of America:

American poetry has been going gangbusters since the turn of the nineteenth century. Twentieth century American poetry is so volatile, so varied, so wise in how it works off of un-American traditions that I sometimes just have to suck my breath in and take a moment to calm down when I think about it. I've never worried about the health of our poetry . . .