Cadiz was founded in 1803 at the junction of westward roads from Pittsburgh and Washington, Pennsylvania, and named after Cádiz, Spain.

[11] In the early and mid nineteenth century, several local families operated stations and served as conductors in the Underground Railroad, helping runaway slaves escape to Canada.

[10] Early industry was based on agriculture and processing farm products.

[12] Coal mining, both underground and surface, became the prominent industry through most of the twentieth century.

More recently the development of the Marcellus Shale in the surrounding area has made Cadiz a center for natural gas production.

The MarkWest Complex, opened in 2012, processes more than 180 million cubic feet of natural gas per day for shipment via pipeline to Mont Belvieu, Texas.

There were 1,590 housing units at an average density of 178.6 per square mile (68.8 km2).

There were 1,524 housing units at an average density of 172.5 per square mile (66.6/km2).

The 4.98 million dollar levy for the creation of a 190,000-square-foot school complex will be able to house 1,550 students.

[23] Ground broke on the new building in August 2017, and opened in the fall of 2019.