This postcard was put out by Clergy and Laity Concerned more than 20 years ago (I've had it a long time, and likely purchased it at either the Strand or St. Mark's book store -- someplace downtown). Dr. King is revered today, but he took a risky and unpopular stand back in 1967 when he opposed the Vietnam War in a speech at Riverside Church in NYC. He was an early co-chair of the CLC.
The King quote on the back, from the Riverside address, is perhaps not as widely known as the "I Have a Dream" speech:
"A nation that continues year after year to spend more money on military defense than on programs of social uplift is approaching spiritual death." (April 4, 1967, exactly one year before his death.)
An interfaith group opposed to war -- whether in Iraq or Gaza -- carries on the work today: