Significant events for area code 414
| Date |
Details |
| 1947 | One of the two original area codes for Wisconsin, covering the southern and central eastern areas of Wisconsin |
| 1955 | Area code 414 was split with 608 covering southwestern Wisconsin |
| July 26, 1997 | Area code 414 was split with 920 covering the central eastern area of Wisconsin |
| September 25, 1999 | Area code 414 was split with 262 covering most of south central Wisconsin, surrounding 414 |