Spanish military commander in California who sided with the United States during the Mexican-American War, helping to shape its transition from Mexican district to an American state (1807–1890). Scarce ANS, signed “M. G. Vallejo,” one page, lightly-lined, 6.5 x 3.5. Boldly penned untranslated note in Spanish, apparently a response to an autograph request. Light scattered foxing and slight show-through from writing to reverse, otherwise fine condition. RR Auction COA.