Alpha, IL has a population of 587 and is the 18,566th largest city in the United States. The population density is 1,827 per sq mi which is 722% higher than the Illinois average and 1916% higher than the national average. The median age in Alpha is 42 which is approximately 13% higher than the Illinois average of 37. In Alpha, 71% of the population over 15 years of age are married, 97% speak English and 1% speak Spanish. 81% of Alpha residents were born in Illinois, 18% were born out of state, 0% were born outside of the United States and 1% were foreign born.