Duncan, lying three miles from the border of New Mexico in the extreme southeastern corner of Greenlee County, is only twenty miles from Clifton, The traveler, leaving Hannagan Meadow high in the White Mountains and descending the wilderness of the Coronado Trail to the broad and fertile reaches of the Gila Valley near Duncan, where every level acre is under cultivation, and many thickets of cottonwood trees has a setting for farmhouse or ranch dwelling, is apt to feel that he has reached another planet. But the impression is simply another example of Greenlee County contrast; another aspect of the wide diversity of its geography and terrain.

Duncan is different, it belongs to the Gila, the storied river of the west, the ageless natural highway whose passage through the mountain and desert southwest has served mankind since prehistoric times. Cliff dwellers, Conquistadors, Apache warriors, mountain-men, Westering immigrants, bad men and good - each in their time has traveled its banks. In modern times, the Arizona communities along the Gila grew up around the stage and freight stations and the military posts which began to bloom in the valley as the country opened to settlement around the middle of the 19th century. As one of these, the site of contemporary Duncan had its origin sometime in the seventies. Called Purdy in the Post Office register of 1883, it was founded by two men named Purdy and Bachelor as a way station on the ore haulage line that ran between Clifton and Silver City, New Mexico. At that time, the location was on the north bank of the Gila, opposite the present townsite.

In 1881 and 1882, when the Arizona Copper Company was formed at Clifton-Morenci, the influx of Scottish capital financed the building of a narrow gauge railway from Clifton to Lordsburg, New Mexico, which the Southern Pacific had reached with standard gauge trackage. When the line, called the Arizona and New Mexico Railroad, passed through Purdy, the settlement was moved to the south bank of the river and renamed Duncan, after Duncan Smith, the managing director of the Arizona Copper Company. With the advent of rail travel the move toward settlement of the valley increased rapidly as farmers and ranchers moved in to cultivate the vase expanse of naturally irrigated acreage. Soon Duncan already assured of the mining town market in the north, became a shipping point for markets in the middle west and east as well. Duncan has been prospering along those lines ever since. A rural community to its core, it derives from the immensely rich and fertile Gila Valley a stability that might well be envied by centers considered to be more "urban", or more in the frenzied mainstream of contemporary American life. The population, between 1,100 and 1,200, shows small change from one census to the next. There is little onward movement, except for youngsters bound for college, or those to whom the traditional occupations do not appeal. A high percentage of the families are in their third or fourth generation of residence. If contentment and well-being are valid hallmarks of the good life, then Duncan, in the valley of the river of the sun, has going for it all that anyone could want.