[1][3] Shortly thereafter and unhappy with AT&SF rates, the line was extended to Benson, Arizona, to connect with the Southern Pacific Railroad.
[1][3] James and Dodge had acquired the Moctezuma Copper Company in the state of Sonora in Mexico, and in 1902 the El Paso and Southwestern line was extended south from Douglas to the Mexican town of Nacozari de García.
[3] The purchase of the Dawson Railway in 1905 extended the railroad to Dawson, New Mexico, where Phelps Dodge had recently acquired coal mines to feed its smelting operations[1] Near Deming, New Mexico, the new track had to cross the line of the Southern Pacific Railroad.
[8] In one day, the El Paso and Southwestern ran more than 500 fully laden hopper cars across the new junction to establish a right-of-way.
[8] Historian David Leighton wrote, that in February 1910, James Douglas, head of the Phelps Dodge Corporation, announced his plan to make Tucson the western terminus of the El Paso and Southwestern Railroad.
The extension was from Fairbank, Arizona, (now a ghost town about 10 miles west of Tombstone) to Tucson, which had beat out Florence and Phoenix for this honor.
By October 1911, there were forty camps of railroad workers between Fairbank and the Vail train station, with another one in the plans, within six miles of Tucson.
purchasing department, drove in the last spike to complete the rail line, a ceremony witnessed by many Tucsonans.
During the Bisbee Deportation, railroad officials collaborated with their counterparts in the Phelps Dodge mining subsidiaries to deport more than 1,300 striking mine workers, their supporters, and even innocent citizen bystanders from the town of Bisbee more than 200 miles (320 km) to the town of Hermanas, New Mexico.
[9] The worldwide collapse of copper prices after World War I[10] severely affected not only the railroad's financial fortunes but those of the mining companies it served.
[2] In 1924, the Southern Pacific leased the entire El Paso and Southwest Railroad from Phelps Dodge,[2][7] assuming the operation on either October 31 or November 1.
[7] The El Paso and Southwestern Railroad was purchased from Phelps Dodge and merged into the Southern Pacific in 1955; the Texas subsidiary remained until 1961.
[7][13] Southern Pacific sold the line from Benson to Douglas to Kyle Railroads as the San Pedro & Southwestern Railway in 1992.
Southern Pacific 3420, a Baldwin 2-8-0 light consolidation, oil burning, former EP&SW engine, is stored at the Phelps Dodge copper refinery in El Paso, Texas.