The earliest obtainable view of San Diego, from Emory's Notes of a Military Reconnaissance, from Fort Leavenworth, in Missouri, to San Diego, in California including Parts of the Arkansas, Del Norte and Gila Rivers.
After W.H. Emory set off to California with the Army of the West, Lieutenant James W. Abert, with the assistance of Lieutenant William G. Peck, embarked on a three month survey and examination of the newly acquired New Mexican territory. Guided by Emory's detailed instructions, the two topographers and their party rode out through the Rio Grande valley, taking topographic readings and making a meticulous inquiry into the uses and possibilities of the region. They constantly scrutinized and recorded their surroundings, going from town to town noting agriculture production, estimating the population, and examining mineral resources.