Midwest (n.)youdaoicibaDictYouDict[Midwest 词源字典]
1926, in U.S. geographical sense, from earlier Midwestern (1889) in reference to a group of states originally listed as W.Virginia, Kentucky, Tennessee, Missouri, Kansas, and Arkansas; now generally meaning states somewhat further northwest. Related: Midwesterner.[Midwest etymology, Midwest origin, 英语词源]