ORIGINAL: BigJ12
The history of releases goes back to the ancient Chinese and the Turks, who used a thumb type release to set arrow flight distance records which were not equaled until modern times. The advent of the modern release began in the 1960's, but these releases were shot on command and were of limited help for increasing accuracy or helping with a target panic problem. The change that revolutionized freestyle archery occurred in the late 1960's with the introduction of the plastic ledge type of release.
Best I could do
There's not a whole lot of "google search" type of info out there on this , unless I'm using the wrong key words. I'm not even sure I know the 100%correct answer , so if anyone can help us out here , I'm using this as a learning experience. I put the last sentence of your reply in bold because thats the area we're looking for.