Ottumwa was a city located in the state of Iowa in the United States of America on Earth.
In 2038, Walter O. Raymond, the son of Cheryl G. Raymond and Wil W. Lachance Raymond, was born in this city. (TNG: "The Neutral Zone", okudagram)
This information came from the remastered Clare Raymond family tree. Walter O. Raymond was named after Walter O'Reilly, a character from the dramedy M*A*S*H. This character was from Ottumwa.