Drew,
This is the previous version of the $2 note than what you collected as this one is series 1953. It's what was in circulation between the current iteration and the previous silver certificate. If you notice it still has the phrase "will pay to the bearer in demand" between the "United States of America" and "Two Dollars" at the bottom center of the obverse.
As to the history of the note, the first was authorized as a continental note for national defense way back on June 25th, 1776 - 9 days before we officially became a country!