He has my R. N. as a monogram on all his note-paper

Original title: Concealed geography 35

Puzzle

He has my R. N. as a monogram on all his note-paper.

Hints

Hint 1
City

Hint 2
in old Greece

Hint 3
also a city

Hint 4
in several states in the US

Loyd, Sam [1914]. in Loyd, Sam, Jr.: Sam Loyd's Cyclopedia of 5000 Puzzles Tricks and Conundrums (in English). New York: Lamb Publishing company, page 10.