WHIPPLE, Lieutenant Amiel Weeks (1818 – 1863). Report of the Secretary of War, communicating, In answer to a resolution of the Senate, the report of Lieutenant Whipple's expedition from San Diego to the Colorado. 31st Congress, 2d Session. Senate. Ex. Doc. No. 19. Washington: 1851.
The joint Boundary Commission "held its first meeting on July 6 near Punta de los Muertos, the site of what later became New Town.14 The essential task facing the delegation involved the plotting of the boundary's western terminus in the Pacific, and the exact location of the confluence of the Gila and Colorado rivers. According to the terms of the Treaty, a straight line would be drawn between these two points separating Upper California from Lower California. Major Emory took charge of determining the initial point in the Pacific, while Gray surveyed the port of San Diego. Whipple, just recently arrived from Panama, was given the task of charting the junction of the Gila and Colorado. The job of gaining a basic knowledge of some of the topography between these two points, so they could be connected in longitude by gunpowder flashes, was assigned to Lieutenant Hardcastle.15 The role the Mexicans played in these operations was of necessity minimal. The inferiority of their survey equipment allowed them to do little else than assist the Americans and help confirm results.16
"As each survey team got underway, Whipple began coordinating his own expeditionconsidered more difficult and extensive than the other two. His men would travel the farthest distance from the base camp in San Diego, crossing the Colorado Desert through an area for the most part unmapped and inhabited only by wandering bands of unpredictable Indian tribes" (Thomas L. Scharf online).
The Treaty of Guadalupe Hidalgo (1848) at the end of the Mexican War called for a joint commission to run the new boundary line between the United States and Mexico. "The Mexican commission under General Pedro García Conde had been reasonably stable from its appointment, but the United States had no such luck. Between 1848 and 1850 three U.S. chief commissioners had been appointed; the first died, the second was removed, and the third resigned before taking up his work. Bartlett, excited over the prospects of combining ethnological and scientific exploration, accepted the position on 19 June 1850. The job was a sensitive one, reflecting political and sectional tensions.
"The commission, 140 men, assembled at Matagorda Bay in August and proceeded to El Paso, where they met their Mexican counterparts six weeks later. The Americans were already racked with dissension. Dismissals and replacements were necessary, but the delay gave Bartlett time to start a remarkable series of drawings and watercolors. The actual work of the survey did not begin until 24 April 1851. Shortly afterward Bartlett and García Conde determined the initial point and the subsequent westward line at 32° 22'. Their decision would lead to much controversy since this line deprived the United States of the Mesilla Valley, which was particularly desirable, if not essential, for the southern route of a transcontinental railroad. The choice of the initial point bred dissension between Bartlett and Andrew B. Gray, James D. Graham, and, later, William H. Emory, scientists on the expedition. These and other critics contended that he had surrendered a sizable chunk of territory, roughly 50 miles wide by 190 miles long, the approximate size of Massachusetts. Bartlett did what he felt was called for in the treaty, without reference to larger geopolitical questions, but the matter festered until the United States bought the parcel in the Gadsden Purchase of 1853.
"The route surveyed went up the Rio Grande to Dona Ana, west and north to the Gila, and down that river to its confluence with the Colorado. The southern boundary of California had already been marked. Throughout the entire survey and on side excursions, the U.S. commissioner continued to sketch, to collect specimens of plants and animals, and to observe languages and cultures of the native tribes. His specimens and notes were eagerly received in scientific societies such as the Smithsonian Institution" (Robert V. Hine for ANB).