Who is Mr. Morrisey from The Lost Continent: Travels in Small-town America and what is their importance?

Mr. Morrisey is the deaf milkman, who delivered milk to the Bryson house each morning. Bryson notes that Morrisey was about sixty, wore a hearing aid and had a dog for a companion. Morrisey talked loudly, as he was unable to hear the level of his own voice.