The first Action of Immediate Witness was issued at the very first Unitarian Universalist General Assembly, in 1961. Actually, they were called Resolutions of Immediate Witness back then. In this inaugural act of witness, the UUA went on record as opposing United States military action against Cuba.
There followed a great lull. No Action/Resolution of Immediate Witness was issued for the next twenty-five years. Finally, in 1986 a second Resolution of Immediate Witness was proclaimed, condemning racism against Arabs in the United States. This let the genii out of the bottle, and every year thereafter the GA has announced new Actions of Immediate Witness. Not only the frequency but also the number have substantially increased, such that only six are now allowed to be issued annually. They have also dramatically increased in wordiness overall–the first one in 1961 had only 69 words (a single somewhat run-on sentence), whereas the average word count for last year’s Actions was 448 (about one page each).