The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
An area in extreme southern New Mexico and Arizona south of the Gila River. It was purchased by the United States from Mexico in 1853 to ensure territorial rights for a practicable southern railroad route to the Pacific Coast.