Chicago originally utilized area code "312" which was one of the original area codes assigned to Illinois in 1947. In 1996, area code 312 was split to form area code 773. All-Lynn-One pays homage to the Windy City with an authentic representation of Chicago--by incorporating Chicago's flag in the 3 and what Chicagoans will forever know as "The Sears Tower" as the 1 in 312.