01) The Gadsden Purchase and the discovery of Silver & Copper.

The Gadsden Purchase, finalized in 1854, was the last major addition to the territory of the contiguous United States. It's acquisition finally settled the boundary between the US & Mexico following the war between those countries during the years 1846-48. Political and economic powers in the the southern US states wanted the purchase to include land as far south as possible to facilitate a transcontinental railroad with the easiest grades and access to the Gulf of California. Negotiators for Mexico held fast on stemming the loss of territory, but were a bit surprised by the eventual American offer to have the border much further north than they had originally desired for the railroad. The odd boot heel of New Mexico and the angled southern edge of Arizona are due to the desire of the United States to get the deal completed while retaining as much of mineral rich lands in the region as was possible. The location of the bend in Arizona's border is directly attributed to the suspicion that the Santa Rita Mountains were rich in copper.

The Civil War delayed the construction of the transcontinental railroad. A worthy item of note is that the western most battle of the civil war occurred about 50 miles northwest of Tucson at the Battle of Picacho Peak on April 15^th, 1862, ending in a Confederate victory.

After the war, western expansion continued and mining claims became more productive. By 1880 the Southern Pacific Railroad had reached Tucson from the west

During the Summer of 1877, members of the 10^th US Cavalry were scouting for Apaches. Nearing the southern end of the Sulphur Springs Valley and the Mexican border, they turned west into a canyon on the eastern slopes of the Mule Mountains to find water for their horses and themselves.

Noticing the rusty looking rocks and that the spring water they found also had an iron taste, they drank what they could. Since it was late in the day, they camped and the next morning scout (Sgt.) John Dunn searched for better water and soon found a silver float in the creek. Informing Lt. John A. Rucker & T. D. Byrne of the find, they looked around a bit more, but their duties took presidence. They later returned to the area for further exploration, eventually locating the Rucker mining claim. Just one day before they found their claim, Ed Schieffelin located his Tombstone silver claim, just 25 miles to the northwest. As early as 1878 a few more claims and a small furnace of Mexican design to smelt the ore was was installed and the mines and community in the canyon began to grow.

Next Chapter - The Transcontinental Railroads & the New Mexico & Arizona Railroad