Missouri was originally slated to receive only two area codes--314 for eastern Missouri (including St. Louis), and 816 for western Missouri, including Kansas City; however, when area codes began use in 1951, southwestern Missouri was assigned 417.
Missouri was originally slated to receive only two area codes--314 for eastern Missouri (including St. Louis). This was including Kansas City. Missouri was originally slated to receive only two area codes--816 for western Missouri. This was including Kansas City. Southwestern Missouri was assigned 417. This was however. Area codes began use in 1951.