All of those books don't seem to be college material...more high school. I read half of them during my internment in the hell hole that is Senior High School. but oh well.
Hawthorne, Cooper, and Poe are canonical, definitely, and that's part of the interest in an M.A. English course. Why have they continued to be read, in every high school English classroom in America for going on 200 years? And why are they read rather than authors such as Susanna Rowson?
Charlotte Temple was the most popular novel in America at its time, but no one's heard of it today.
Consider that Shakespeare is commonly read in high school classrooms, but a university campus would be remiss not to have a Shakespeare scholar holed up in an office somewhere in the English department--just because books are read in high school doesn't mean they're not worthy of critical literary study.
(Also you probably didn't read 400 pages per week in your high school English class.)