Before dawn on December 6, 1846, Brigadier General Stephen Watts Kearny and one hundred exhausted men of the U.S. 1st Dragoons rode down from the freezing rain of the Santa Ysabel hills into the thick white tule fog of the San Pasqual Valley—just thirty miles northeast of Old Town San Diego. After an 1,800-mile march from Santa Fe across the Gila River and the scorched Anza-Borrego badlands, their boots were rotting, their mules were half-starved, and the paper cartridges in their Hall carbines were soaked with winter rain. Waiting for them in the mist were Captain Andrés Pico and eighty Californio Lancers—the finest light horsemen in North America, mounted on fresh ranchero steeds and armed with eight-foot ashwood lanzas and braided rawhide reatas.In this special 51-minute long-form episode of American Tapestry, we tell the complete five-act story of the bloodiest engagement of the Mexican-American War in California. Follow Kearny's fateful October 1846 encounter with legendary scout Kit Carson along the Rio Grande; the misunderstood "Trot / Charge" order that strung the American cavalry out across half a mile of wet valley floor; and Pico's deadly feigned retreat that cost the lives of twenty-one American soldiers—including Captains Abraham Robinson Johnston and Benjamin Daviess Moore. Then, climb the jagged granite boulders of Mule Hill, where the starving, surrounded survivors ate their own pack mules while Kit Carson, Navy Lieutenant Edward Fitzgerald Beale, and a twenty-three-year-old Kumeyaay scout named Chezmeh took off their boots, abandoned their rattling canteens, and crawled barefoot through twenty-nine miles of prickly pear cactus and enemy patrols to summon Commodore Robert F. Stockton's two hundred Marines and sailors from Old Town San Diego.