Area code 312 covers the downtown area of Chicago. The 312 area code is one of the original areas codes introduced in 1947. Area code 312 originally covered all of the Chicago area, but area codes 708 and 773, added in 1989 and 1996, now cover Chicago's suburban area.Continue Reading
Area code 312 is one of the smallest area codes in the United States, covering only a few square miles. Nevertheless, the area code contains a large number of people, as it covers Chicago's dense core. Area code 872 overlays area code 312, and callers must dial area code 312 before making calls, even within the 312 area code region.
Chicago is the economic and cultural heart of the American Mid-West. Chicago is a center of manufacturing, retail and agricultural trading. The Chicago Board of Trade is the world's largest futures market for agricultural products. The city is located on Lake Michigan, one of the five Great Lakes, and serves as a major Great Lakes port.
AT&T and Bell Laboratories developed area codes in the 1940s to replace an increasingly overburdened system that relied on operators manually switching wires. AT&T and Bell Laboratories selected digits for the original 86 areas codes based on the design of rotary phones, assigning easy-to-dial area codes to areas with higher population densities.Learn more about The Midwest