The city of Benson was founded in 1880 along a siding of the Southern Pacific Railroad. The town was named in honor of Judge William B. Benson of California, a friend of the president of the Southern Pacific. There had previously been a stage station on the Butterfield Trail Stage Line just north of present-day Benson.

As demand for copper and silver grew in the early 1900's, Benson grew, too. The ores were mined in the San Pedro Valley and shipped to Benson for smelting and then distribution via the railroad line. A rail line was built by the El Paso & Southwestern to connect Benson with Tucson. A third set of tracks, the Sonoran Railroad, connected Benson with Guaymas, Mexico on the Sea of Cortez.

While Benson bills itself as the Gateway to Kartchner Caverns State Park, Benson is also the gateway to Tombstone to the south and to the Redfield Canyon and Galiuro Wilderness Areas to the north. Benson is also home to the Astronomer's Inn Vega-Bray Observatory with 8 major telescopes from 6 to 20 inches in diameter, located on a hill outside of town overlooking the San Pedro Valley. With temperatures about 11° cooler than Tucson in the summer, Benson is growing in popularity as a retirement community and tourism destination.