A ''minor skirmish'' (for some), in the opening Months of The Mexican-American War (1846-1848), The Battle of San Pasqual (California), was the end result of a forced march by elements of The US Army. In the opening weeks of The War. The US Army moved a Force of close to 1,500 Officers and Men, from Kansas (by foot and horse), Southward into Mexican Territory (into what would become New Mexico and Arizona Territories). The goal was to meet up with a US Naval Squadron of (4) Frigates and a Force of 500 US Marines and Naval Infantry (who had taken San Diego). After many weeks of forced marches, The US Army Force at last made it to the plains of California. From their, they were to met up with Naval Forces and march Northwards to ''take'' The Cuidad de Los Angeles. But The US Force ran afoul of Mexican Defenders under Jose Mas Flores. The 100-odd Mounted Lancers encircled and – after several Charges, thought they had The ''Americanos''. But the doggedness of The American Troops played out. Defeating The Mexican Lancers (and running out of ammunition as well), the Relief Force of US Marines and Naval Infantry arrived from San Diego – just in time. The Site today is a modern battlefield Historic Park, visited by hundreds each year. But The Museum also has ''other Visitors'' on occasion. These are thought to be Spirits of both American and Mexican Soldiers who fought and died on The Field.
Staff Members of The Museum have reported for years, of ''voices'' (whispers in fact), which ''speak in 19th Century terminology'' and act as though ''they are fighting in a battle''. In fact, a portion of The Museum does rest on a portion of the actual battlefield. Several Paranormal Investigations using Electronic Voice Phenomenon (EVP), have even ''picked up'' several ''Proper Names'' of Soldiers who fought in the fray. In addition, ''Cold Spots'' – which move throughout The Museum bear out ''something is still there''. Finally, People have reported catching the ''shadowy glimpse'' of ''Mounted Horsemen'' galloping across the plain....Perhaps the Spirits of The Mexican Lancers?