Miss Field's Seminary (also known as the Home School for Young Ladies, or simply Field Seminary) was a school for young women and girls founded in 1872 by Miss H.N. Field.
It was originally at 529 Hobart St. (now 21st St.), 2 which was later the site of the Sackett School. The photo from the California State Library has 423 Hobart written on the back, 1 but no such address can be found on the 1889 Sanborn maps. In 1879, the school moved to 1825 Telegraph in the Knox House, 2 about where present-day 27th St. is.
H.N. Field died c.1883, and her sisters Lucy A. Field and Caroline H. Field took over running it. They had been involved since about 1879. 3 An 1886 ad lists Miss L. Tracy as principal. 4 It's not yet known when the school closed. It still appears in the 1892-1893 directory, with Mrs. W.B. Hyde, principal. 5 The building on Telegraph was sold and demolished in 1898. 6