Area Code 412 History - Pennsylvania

Significant events for area code 412

1947 One of the four original area codes for Pennsylvania. It covered the southwestern part of the state.
1998 Area code was split with 724 surrounding 412 (a "doughnut').
2001 Area code 878 was overlaid on 412 and 724 , but was not used until 2013 (but only in the 724 area for the time being).