Question: Which Maine county had a 2010 population of over 50,000 and was where the designer of the Eaton School began his career?
Sentence (from "Eaton School (Norridgewock, Maine)"): The Eaton School, in Norridgewock, Maine, also known as Somerset Grange #18, is a historic community building at Main Street and Mercer Road in Norridgewock, Maine.
Relevant evidence: Yes