Some additions:

Tristram Potter Coffin and Henning Cohen, The Parade of Heroes: Legendary Figures in American Lore (Anchor Press/Doubleday, 1978, 630 pp.) ["a collection of songs and ballads, tales and anecdotes, rhymes and sayings about folk heroes known and obscure"]

Duncan Emrich, Folklore on the American Land (Little, Brown, 1972, 707 pp.) ["contains chapters on everything from children's rhymes to epitaphs, including folk beliefs and superstitions, proverbs, legends, tales, folk language, songs and ballads, sections on the folklore of birth, marriage, and death, and much more"]

Richard M. Dorson, Buying the Wind: Regional Folkore in the United States (University of Chicago Press, 1964, 574 pp.) ["The collection explores rich and distinctive lore of Maine Down-Easters, Pennsylvania Dutchmen, Southern mountaineers, Louisiana Cajuns, Illinois Egyptians, Southwest Mexicans, and Utah Mormons."]

Roger D. Abrahams, Afro-American Folktales (Pantheon, 1985, pp. 327) ["These 107 tales come from the canefields of the antebellum South, the villages of Caribbean islands, and the streets of centemporary Philadelphia."]

~Masato