Offered here is the only known Pacific Mail Steamship Company marked Colt Single Action Army Revolver. The Pacific Mail Steamship Company marking, “PM SS Co,” is stamped on the left side of the barrel followed by “45 COLT.” Otherwise the revolver has standard Colt markings, including the one-line Hartford barrel address, two-line patent dates marking on the frame and matching serial numbers on the frame, trigger guard and back strap. The rear cylinder face is marked “03.” Over the years this SAA has been documented in Colt related publications. The revolver is pictured in Jerry Hemphill’s “Colts from Texas and the Old West” on page 33. When this book was published in 1986, Hemphill acknowledged this revolver as the “only known single action stamped P.M.S.S. Co. on the left side of barrel.” The PMSS Co. marking on this revolver is pictured and identified in Keith Cochran’s "Colt Peacemaker Encyclopedia” on page 288. Of interest is the Colt Lightning Revolver no. 108310 stamped with the PMSS Co. marking on the back strap as referenced in Richard Marohn’s article “The Lightning Express Revolver” published in the January 1981 edition of Arms Gazette (issue included). This Lighting and this SAA were both manufactured in 1898. Marohn proposed that Wells Fargo, “the sole freight agent of the Pacific Mail Steam Ship Company,” had arms branded with the PMSS Co. name as well as the names of the other agencies it served. The included factory letter confirms the 7 ½ inch barrel in .45 caliber, blue finish and hard rubber grips. The factory records also show this revolver as being part of a 25 gun shipment on February 5, 1898 and delivered to Colt’s San Francisco Agency, California. In the accompanying May 1981 dated notarized letter, the original owner’s son and inheritor of this revolver recounts, “This revolver was carried by my father, Mr. Elleck Lonnie Angles, deceased, during his duties as Mail Room Guard on various vessels operated by the Pacific Mail Steamship Company. To the best of my recollection, my father was so employed by this company during the years 1907 through 1915. The revolver was given to me by my father in 1954.” An accompanying bill of sale and letter indicates that this revolver was sold in June 2004 by past director of the Colt Collectors Association C.D. Terry (1928-2012). Founded in 1848, the Pacific Mail Steamship Company was originally created to carry U.S. mail along the Pacific transcontinental route via Panama. The California Gold Rush of 1849 created an economic boom for the company nearly at its inception, as it played a key role in carrying supplies and gold seekers. In fact, a PMSS Co. ship carried the first gold seekers from the East to San Francisco. Within five years the company was operating 18 steamers. At its operational peak in 1869, the company owned 23 steamers. Under threat from Confederate raiding parties, PMSS CO. ships carried a detachment of Union soldiers for protection during the Civil War. In 1867, the company began regular service routes between San Francisco and Hong Kong, which opened the East to the West and brought diversity to the shores of California. The PMSS Co. was the most profitable business of its kind while also playing a pivotal role in America’s westward expansion. Competition from the railroad and the company’s own neglect of keeping up with changing technologically ultimately doomed the PMSS Co., which officially closed in 1949 with just over 100 years of service. Includes an original PMSS Co. advertisement from 1905 and an original PMSS Co. label.