Complex sentence: Faulkner is one of the most important writers in Southern literature in the United States, along with Mark Twain, Robert Penn Warren, Flannery O'Connor, Truman Capote, Eudora Welty, Thomas Wolfe, Harper Lee and Tennessee Williams.
Split into simpler sentences: Faulkner is one of the most important writers in the United States. He is also one of the most important writers in Southern literature in the United States, along with Mark Twain, Robert Penn Warren, Flannery O'Connor, Truman Capote, Eudora Welty, Thomas Wolfe, Harper Lee and Tennessee Williams.