Congress, AZ has a population of 1,247 and is the 13,795th largest city in the United States. The population density is 33 per sq mi which is 42% lower than the Arizona average and 63% lower than the national average. The median age in Congress is 67 which is approximately 82% higher than the Arizona average of 37. In Congress, 81% of the population over 15 years of age are married, 94% speak English and 6% speak Spanish. 21% of Congress residents were born in Arizona, 76% were born out of state, 0% were born outside of the United States and 3% were foreign born.