The Union Army is only mentioned in The Hamlet, in the novel's reference to the groups of Union soldiers who patrolled the roads of Frenchman's Bend during the Civil War.
This is the "United States military force" referred to in Requiem for a Nun that "burned the Square and the business district" in Jefferson during the Civil War (37).
The Union Army in Absalom! is an unseen but important force. When "Yankee troops" pass near Yoknapatawpha at some point in the Civil War (66), for example, Coldfield's two Negro servants and "all of Sutpen's" slaves "follow the Yankee troops away" (67).
Two of the Unvanquished stories - "The Unvanquished" (titled "Riposte in Tertio" in the novel) and "Vendee" - refer generically to the Yankee troops after they have left Mississippi: "there ain't a Yankee regiment left," says Ab Snopes in "The Unvanquished" (87, 139). He is wrong, but by the next story they have in fact all moved away to continue fighting elsewhere in the South. In "Vendee," in their absence, Uncle Buck says Grumby's viciousness makes "even the Yankees" look good in comparison (105, 169).
In both Flags in the Dust and "Retreat" as a short story and again as a chapter in The Unvanquished, this company of Union cavalry rides up to the Sartoris plantation hoping to capture Colonel John Sartoris. In all three texts he is able to fool them long enough to escape, but in the last two the Yankees then dig up the family's buried silver and set fire to the mansion.
"Uncle Willy" is the title character in a 1935 short story. His last name is Christian, his first name is probably William, and as the narrator says, "he wasn't anybody's uncle" (225). His story is briefly recapitulated in two later novels, The Town and The Mansion. His story is very un-Faulknerian in its refusal to provide many details about Willy's past. He was born in Jefferson soon after the end of the Civil War, the son of a man who opened a drugstore in town in the 1850s; Willy himself adds the fact that he "graduated from a university" (245).
The "Uncle Job" in The Sound and the Fury works at the hardware store where Jason Compson also works. In one of his racist rants, Jason calls him "an old doddering nigger" (251), but while Jason also complains about Job's laziness, during the course of the day April 6, 1928, he is shown assembling new cultivators and delivering merchandise. Earl, the man both Job and Jason work for, says "I can depend on him" (248).
"Uncle Dick" is white, so the honorific "Uncle" in his case has a different connotation than it does for the Negro 'uncles' in Yoknapatawpha. In "Lizards in Jamshyd's Courtyard," and again in The Hamlet, where the story of hidden treasure at the Old Frenchman's place is re-told, he is "a shriveled little old man . . . with a long white beard" (144, 379). He wears "a filthy frock coat," lives in "a mud-daubed hut" in a swamp, and is reputed to eat "frogs and snakes [and] bugs as well" (144, 381).
Ash, or Uncle Ash, is an old Negro who works for Major de Spain. In the five fictions in which he appears, he is most often seen in the woods, as the cook and chief servant on the Major's annual hunting trips, "a-helping around camp," as Ratliff puts it in "A Bear Hunt," where Ash first appears (67) - though in the last section of "The Bear" in the novel Go Down, Moses he sits in the corner of De Spain's office in Jefferson, pulling the cord on the "bamboo-and-paper punkah" that provides the Major with a breeze in the heat of Mississippi (301).