Re: Major Cities in area code 730...
I was wondering about your list of cities. Usually a telephone area code represents a limited geographic area.
The Pentagon is in area code 703, as are Alexandria, Fairfax, and Springfield (Northern Virginia)
A map of area code 730 is shown at the link below, and it is in Illinois (east of St. Louis)...
https://www.zipdatamaps.com/area-code-730
My search returned this results from here...
https://www.usphonebook.com/730-area-code