Photo crop exposure date: unknown. Exposure date (or window) of subject photo: 1893-1904 Subject: Photo crop of open book showing photograph of US Post Office (1890), north side of Alamo Plaza. Ascription at bottom of book page is THE POST OFFICE AND CUSTOM (sic) HOUSE and a number 20. View of book photograph is NNE at street level from corner of Houston and Alamo Plaza.