Georgia currently utilizes 9 area codes. When first established by AT&T and the Bell System in 1947, 404 covered the entire state of Georgia. The most recently added was 470 in 2010 as an overlay to 770 and 404. Today, 770 is the most populated with an estimated 4.7 million of the state's 9.7 million residents.
Sources: North American Numbering Plan Administration (NANPA), telecom providers, and the U.S. Census Bureau.