Jame Iry sums up the history of programming languages: A Brief, Incomplete, and Mostly Wrong History of Programming Languages. It's hilarious and sort of true:

1964 - John Kemeny and Thomas Kurtz create BASIC, an unstructured programming language for non-computer scientists.

1965 - Kemeny and Kurtz go to 1964.

Predictably, the comments include contributions of other "milestones", and the usual debates over whether something is a "scripting language" or not.