Daguerreotype of street with Adams House in center "The oldest known photograph, taken 1845, shows junction of what is today's Massachusetts Ave. and Mystic St. shortly before the coming of the railroad. The tracks would eventually require the destruction of the Deacon Joseph Adams house. Previously published drawings of the house have turned out to be heavy retouchings of this prmitive photographic image." See Richard Duffy's Images of America: Arlington, page 14. Note, this is an error and it was actually the William / John Adams House. See 1910.2.2A for reprint with more information.
