The New Oxford American Dictionary reports the following definition for Middle America:
Middle America |ˈˌmɪdl əˈmɛrəkə|
1 the middle class in the U.S., esp. when regarded as a conservative political force.
• the Midwest of the U.S.
2 the North American region that includes Mexico and Central America, and often the West Indies.
Middle American noun
Why is Midwest in the Midwest of the U.S. written capitalized?
Compare it with the following definition given for northeast:
1 lying toward, near, or facing the northeast.
• (of a wind) coming from the northeast: there was a strong northeast wind.
2 of or denoting the northeastern part of a specified country, region, or town, or its inhabitants: northeast Baltimore.
In northeast Baltimore, northeast is not capitalized. What is the difference between the two cases?
When I write Middle American to mean an American person of the middle class, why cannot I write middle American?