The A-12’s first flight–unofficial and unannounced in keeping with a Lockheed tradition–took place on 25 (26?) April 1962 and almost caused the loss of the only OXCART aircraft built so far. 

On Feb 3, 1964, an A-12 Blackbird flew March 3.2 at 83,000 feet for 10 minutes

The first flight of an SR-71 took place at the Air Force Plant 32, Palmdale, Calforinia

First Flight of SR-71 and M-21 carrying D-21 drone

Mel Vojvodich (CIA) flew A12 #937 out of Kadena on the First Operational Black Shield Mission.

On January 23, 1968 the USS Pueblo was seized by the North Korean government. Confirmation was made by an A-12 Blackbird.

In 1964 during the Vietnam War U.S. aviators were captured by the North Vietnamese. Paul F Crickmore shares the story of how two SR-71 Blackbirds generated tri-sonic booms to free captured US prisoners of war in his book Lockheed Blackbird: Beyond the Secret Missions (Revised Edition).