3. The discovery of gold in California; 4. The adoption of irrigation farming by an Anglo-Saxon people. In all of these movements the Battalion was an important factor. The part the Battalion took in opening the highways to the Pacific has already been detailed in the story of their march, and fully recognized in the military order already quoted in these pages, and which is now on file as a government document in Washington. =Territory Added to the United States by the Conquest of Mexico.=--"In all," says a reliable authority, "more than five hundred and ninety thousand square miles were added to the territory of the United States as a result of the [Mexican] war." This included the west half of what is now the State of New Mexico, the west half of Colorado, all of Utah, Nevada, Arizona and California. For this territory, which equaled in extent two-thirds of the territory of the thirteen original states of the Union, the government paid Mexico $15,000,000. "Including Texas," says the authority here followed, "the additions of territory were more than nine hundred and sixty-five thousand square miles."[78:a] Or, as another historian states it, "territory equal in area to Germany, France and Spain added together."[78:b] =The Gadsden Purchase and the Battalion Route.=--Commenting on the Battalion's march and the map he made of it, Colonel Cooke says: "A new administration, (this was the Pierce administration, 1853-1857) in which southern interests prevailed, with the great problem of the practicability and best location of a Pacific railroad under investigation, had the map of this wagon route before them with its continuance to the west, and perceived that it gave exactly the solution of its unknown element, that a southern route would avoid both the Rocky Mountains and Sierra Nevadas, with their snows, and would meet no obstacle in this great interval. The new 'Gadsden Treaty' was the result: it was signed December 30, 1853." This purchase added to the territory of the United States forty-five thousand five hundred and thirty-five square miles; for which was paid $10,000,000. The purchase was made by James Gadsden of South Carolina, minister to Mexico, hence the name Gadsden Purchase.[78:c]