San Francisco's Post Office opened by March 15, 1849 and its first postmark was a
manuscript, used from March 15 to June 20. San Francisco began using a postmarking
device on June 20, the straightline illustrated above, with the date written in
manuscript. Rates were indicated in manuscript until devices were obtained later in
1849. In the early years, there was no need for cancels because there were no stamps
available to cancel until the United States 1851 issue.
Three useful sources exist for classifying San Francisco postmarks, rate marks and cancels:
- The most comprehensive is Mahoney, John M., San Francisco Postal Markings, 1847-1900,
La Posta Monograph Series, Vol. 8, La Posta Publications, Lake Oswego, Oregon, 1992.
Mahoney's book includes tracings of postmarks, killers, rate marks and other
- Also important is Williams, John H., California Town Postmarks, 1849 - 1935, Western
Cover Society, 1997, published by Leonard H. Hartmann, Louisville, Ky. This book deals
exclusively with postmarks and contains numerous tracings as well.
- Third is an article by Friend, Clifford L., The 26mm Double Circle Postal Marking Of
San Francisco, Western Express, Vol XXV, No. 1, January, 1975, p. 11-18. This article is
limited to the double circle postmark introduced at San Francisco in September, 1861.
Friend's work is built upon earlier studies by Stanley Ashbrook. Neither Mahoney nor
Williams does justice to the several varieties of this postmark. Mahoney lists them all
as type 79. Williams lists five types, SAF 590, 600, 610, 620 and 630 but gives little
help for distinguishing them.
The two books have their strengths and weaknesses. Mahoney covers a broader field, but
in the early postmarks, there are some omissions and some of the usage dates are suspect.
He also uses a single tracing to illustrate several similar but distinct styles,
sometimes leading to confusion. Williams's book is in two large volumes, covering the
entire state. The San Francisco postmarks are found in Volume 2, but the explanation
key for his listings is found only at the start of volume 1, so you need to buy two books
to get the San Francisco postmarks with the key to understanding the listings. Williams
includes multiple tracings of the early San Francisco postmarks and has a tracing for
each style. However, some tracings have no discernible differences from other tracings
and I find the explanations sometimes inadequate for distinguishing them. I use both
books, except for the double circle postmarks, where I use Friend's types because neither
Mahoney nor Williams do justice to those postmarks. In this website, I attempt to give
type references used by each author. Only postmarks found on Hawaiian mail are relevant
to our study here so many postmarks used in San Francisco will be omitted intentionally.
Others may exist but I have not recorded them. Please send me
an E-mail (firstname.lastname@example.org) with information about other San Francisco pre-1870 postmarks on covers from
San Francisco postmarks are found on most letters arriving from Hawaii, but in this
Period they are rarely found on letters originating on the mainland unless mailed at San
Francisco. The practice of using postmarks on letters transiting the office was some
years in the future. Mail arriving at San Francisco from Hawaii or other Pacific ports
was first entered into the United States mail at San Francisco so the postmark was used
to indicate where the letter entered, rather than merely as a transit mark.
For ease of loading and access, the San Francisco marks are divided into the following sub-pages: