Which land actions gave the United States possession of the southern part
of Arizona and New Mexico, west of the Rio Grande and south of the Gila
River?
(A) Gadsden Purchase
(B) Treaty of Guadalupe Hidalgo
(C) Platte Purchase
(D) Hay-Herrán Treaty
(E) Webster-Ashburton Treaty
It was the "Gadsden Purchase" that gave the United States possession of the southern part of Arizona and New Mexico, west of the Rio Grande and south of the Gila River, since this was instigated by the American ambassador to Mexico at the time.