CVG and CMH Airports

My closest airport, about 30 minutes away, is Dayton International Airport, which has the "DAY" airport code, which makes total sense.  The other two I use are Cincinnati, "CVG", and Columbus, "CMH", which are not so obvious and need some history lessons.

Cincinnati's airport is in Northern Kentucky, and the nearest major city at the time of its opening was Covington, hence the "CVG".

As for Columbus, the "CMH" stands for "Columbus Municipal Hanger", its original name.

https://en.wikipedia.org/wiki/Cincinnati/Northern_Kentucky_International_Airport

https://en.wikipedia.org/wiki/John_Glenn_Columbus_International_Airport