December 6, 1846 is the day the Battle of San Pasqual took place between the United States led by Brigadier General Stephen W. Kearny and the Californios led by Major Andres Pico. This battle was one of the bloodiest in the U.S.-Mexican War and ended in controversy.
In order to conquer California for the United States the Army of the West marched from Fort Leavenworth across the southern desert where they tackled such issues as lack of water, lack of food, and poor conditions in June 1846.
That was when Brigadier General Kearny received word that California was in American hands and everything was secure on the Pacific Coast. Due to this misinformation, he sent two-thirds of his men back to Santa Fe and continued west with only 100 men. The eastward scout Kit Carson was put into service as a guide for the army troops as they moved onward.
The journey across the desert took its toll on the men and their mounts. When they finally camped at Santa Maria on December 5, 1846 they were hungry and exhausted from the rain.
Nearby, the Californio force led by Major Andres Pico camped at the Native American pueblo of San Pasqual. Hearing about the Californios presence in the area Brigadier General Kearny sent a nighttime reconnaissance to investigate the Californios camp. The plan was foiled due to the amount of noises and the Californios prepared for battle.
At dawn on December 6th, the U.S. troops rode over the hills between Santa Maria and San Pasqual to face the Californios in the valley below. The Californios lances proved to be an advantage over the U.S. troops swords and rifles with wet gunpowder. Eighteen soldiers were killed in battle, three died of wounds, and one went missing in action. Pico reported that only one Californio was killed.
That night, the U.S. forces buried their dead, patched up the wounded, and tried to continue to San Diego the following morning. But they were stopped right past Rancho San Bernardo at what is now called Mule Hill....