The modern history of the city is centered around agriculture, particularly cotton. Coolidge was founded in 1925 when R.J. Jones laid out an site during the construction of the Coolidge Dam on the nearby Gila River, which was completed in 1930. Both the dam and the townsite were named for Calvin Coolidge, the 30th President of the United States. The dam made the sandy soil native to the area into very rich farmland, and soon vast expanses of desert were plowed and acres of cotton were planted. This is when the area's status as the hub of the Arizona cotton industry was solidified and led to the incorporation of Coolidge as a city in 1945.