Quentin goes to Cambridge, Massachusetts, to attend Harvard College. When the "Appendix" says that he "waited first to complete" his freshman year before committing suicide (331), Faulkner revises the story he told in The Sound and the Fury.
The first Compson to arrive in Yoknapatawpha, according to Faulkner's "Appendix" to The Sound and the Fury, travels there from Kentucky along the "Natchez Trace" (328). Originally created by Indians, the Trace was a 440-mile trail through the wilderness between Nashville, Tennessee, and Natchez, Mississippi. It linked three rivers - the Cumberland, the Tennessee and the Mississippi. In the 18th and early 19th centuries, it served as a major overland route for traders and settlers.
Before Jefferson had a name, before it was even a village, it was a Chickasaw agency - the place where the indigenous population of the region interacted with an agent appointed to represent the federal government in its dealings with them. The "Appendix" that Faulkner wrote to The Sound and the Fury describes the agency as a "long rambling onestorey mud-chinked building" that is home to "the Chickasaw Agent" and a "tradingpost store" (325).
Faulkner traveled to Paris in 1925, just before he began writing his first Yoknapatawpha fictions. He went as an aspiring artist, and getting a glimpse of James Joyce at the Shakespeare & Company bookstore in Paris was an item on his itinerary. Among his characters who also spend time in Paris are Temple Drake in Sanctuary; in fact, the last page of that novel, describing her state of mind while seated in the Luxembourg Gardens in Paris, is a slightly revised version of a piece of prose Faulkner wrote while sitting in the same place himself during his trip.
There is no bookstore in Jefferson, and only one mention of a public library in any of the fictions. The county library is mentioned in the "Appendix" that Faulkner wrote for The Sound and the Fury. Its account refers to several of the books on the library shelves by name or at least by type: "Forever Amber" and "Jurgen and Tom Jones," and various "volumes of Thorne Smith" (333).
