The kind of cotton grown by the Pimas was first domesticated in tropical Mesoamerica over 2000 years ago. From there, its use spread in all directions. It arrived in southern Arizona and western New Mexico around AD 500. The residents of this region cultivated cotton for their own use and for trade to societies living farther north. By about 800 years ago, this trade declined because the northern societies developed a new variety of cotton that they could grow locally.

Today, Pima cotton is world famous because its fibers, or "staple," are longer than those of other varieties of cotton, which yields an especially soft cloth. But today's Pima cotton is not the same variety that the Pimas used in the 19th century and earlier. Modern Pima cotton was developed in the 19th and 20th centuries by crossing cotton varieties from the Americas with tree cotton from Egypt. The hybrid was then introduced to the United States, especially Arizona, Texas, New Mexico, and California. It was named Pima cotton in honor of the Pimas who helped raise the cotton in the early 1900s on an experimental farm in Arizona run by the U.S. Department of Agriculture.