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

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 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

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).