The approximately 30-by-30-mile (48-by-48-km) Amusgo territory straddles the Oaxaca–Guerrero border. Only about 5,000 of 40,000 Amusgo speakers live in Oaxaca, around the small centers of Cacahuatepec and San Pedro Amusgos, while the remainder live on the Guerrero side, near the centers of Ometepec, Xochistlahuaca, and Tlacoachistlahuaca.

Linguists reckon that the Amusgo language, a member of the Mixtec language subfamily, separated from Mixtec between 2000 and 1000 B.C. Around A.D. 1000 the Amusgos came under the domination of the strong coastal Mixtec kingdom of Tututepec. In 1457 they were conquered by the Aztecs and not long after, by the Spanish in the 1520s. Decimation of the Amusgo population by disease during the 16th century led to the importation of African slave labor, whose descendants, known locally as negros or costeños, live along the Guerrero–Oaxaca coastline.

Although the Amusgo population eventually recovered, many of the old colonial-era haciendas remained intact until modern times. The Amusgos, isolated from the mainstream of modern Mexican life, retain their age-old corn-bean-squash farming tradition. Moreover, they have received little attention from anthropologists or archaeologists, although several likely archaeological mounds exist near Amusgo villages.

Amusgo women are nevertheless famous for their hand-embroidered huipiles, whose colorful floral and animal designs fetch willing customers in Oaxaca tourist centers. Even better, Amusgo women often wear their huipiles, appearing as heavenly visions of spring on dusty small-town side streets.