The first mining railroad in Arizona was built in the late 1870s and ran along the Coronado Trail to Morenci.
The Coronado's first train, which was affectionately named, "Little Emma" was built by the H. K. Porter Company of Pittsburgh, Pennsylvania in 1880 and arrived on site early the same year — about a year after the railroad was built. Until then, mules had run the railroad, pulling empty ore cars up to Henry Lesinsky's Longfellow Mine. Once every car but the last was filled, the mules and mule-skinner boarded the empty car for the downhill run to Lesinsky's smelter.
The Coronado was called a "baby gauge" railroad because there were 20 inches between its tracks, instead of the standard 56.5 inches. It stretched from the foot of the Longfellow Incline down Chase Creek Canyon to Clifton, a distance of four or five miles. Though Emma was "about as large as a good-sized coffeepot," it weighed around 9,000 pounds (11 tons), measured only 17 feet long, and was about 5 feet 5 inches wide. To transport the locomotive across the country it had to be disassembled and boxed for shipping. It traveled from New York City, around Cape Horn to San Francisco, by rail to Fort Yuma and ox team to Clifton.
When the train was put back together, they found that someone at H. K. Porter had misspelled its name — rendering it as "Coranada" instead of the intended "Coronado." It's name was soon changed to "Little Emma" after one of the daughters of the locomotive's engineer, Henry Arbuckle. Some of the residents, however, gave it a different name, "El Vapor," for the steam it produced.
Before selling his mining interests to the Arizona Copper Company in 1882, Henry Lesinsky bought two more baby gauge trains. Arizona Copper was pleased enough with their performance that it expanded the fleet to at least ten engines running the line at a time. So was the Detroit Copper Mining Company, which bought some of the little trains for its own operations.
Among Arizona Copper's other purchases were Locomotive No. 2 "Grant" which now resides outside the Arizona Mining & Mineral Museum on static display, Arizona Copper No. 5 "Forman"which now resides at the Morenci Plaza in the middle of a parking lot on static display, Locomotive No. 7 "Rattlesnake" which now resides at the Arizona Railway Museum in Chandler disassembled and awaiting restoration, and Locomotive No. 8 "Copperhead" which is currently on static display next to the old Clifton Cliff Jail.
The tiny trains that ran the Coronado Railroad "with remarkable speed and safety" were eventually retired in 1922 when the Coronado Railroad ceased operations. Most of the rolling stock was used for scrap metal while others were simply just left behind at the abandoned mining sites.
Little Emma no longer exists — its exact fate is uncertain — but its name lives on. A Phoenix brewery, the Wren House Brewing Company, named one of its products "Little Emma" after the first train in the Clifton-Morenci area.