Hey Bryan,
In addition to what Adam said:
1) first commit December 2013 before I settled on "Phoenix" name. Inception maybe a few months prior
2) 1.0 released Aug 28, 2015
3) Changelog includes all release dates for major/minor
4) Other important dates would be:
- José joining the phoenix-core team ~ Sept 2014
- ElixirConf 2014 (first elixir conf) where my Phoenix talk was really a takeoff point for exposure. Also the upcoming "Elixir and Phoenix Conf" in Orlando later this year.
Hope that helps and good luck with the presentation!