Coolidge is a city in Pinal County, Arizona, United States. According to the 2010 census, the population of the city is 11,825.According to the United States Census Bureau, the city has a total area of 5.0 square miles (13 km2), all of it land.
Coolidge is home of the Casa Grande Ruins National Monument. The monument was the first historic site to receive protected status by the United States Government in 1892. The ancient city was built about 1200 AD. by the Hohokam people.Coolidge was founded in 1925 and incorporated as a city in 1945. It is named for Calvin Coolidge, the 30thPresident of the United States.Formerly, the town was home to a station for Amtrak.