Douglas is a city in Cochise County, Arizona, United States. Douglas has a border crossing with Mexico and a history of mining.Douglas stands on the U.S.-Mexico border, across from the city of Agua Prieta, Sonora, Mexico.Douglas is home to the historic Gadsden Hotel, which opened in 1907. Named for the Gadsden Purchase, the stately five-story, 160-room hotel became a home away from home for cattlemen, ranchers, miners, and businessmen. The hotel was leveled by fire and rebuilt in 1929. The Gadsden is recognized as a National Historic Site.The Douglas Grand Theatre was built in 1919 and was the largest theater between Los Angeles and San Antonio.