Adam P. Leighton House - Adam P. Leighton House is an historic house in Portland Maine. Located in the Portland's West End it was built in 1902-03 and listed on the National Register of Historic Places in 1982. It was the home Adam P. Leighton who was considered the father of the American postcard industry and served as the Mayor of Portland from 1908-09. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
A:
Building