Bill Shankel was born in 1939 in Angels Camp, California. He enlisted in the Naval Aviation Cadet Program on February 9, 1961, and was designated a Naval Aviator at NAS Kingsville, Texas, in August 1962. After completing A-4 Skyhawk Replacement Air Group training with VA-125 at NAS Lemoore, California, ENS Shankel served with VA-94 at NAS Lemoore and deployed aboard the aircraft carriers USS Ranger (CVA-61) and USS Enterprise (CVAN-65) from March 1963 until he was forced to eject over North Vietnam and was taken as a Prisoner of War on December 23, 1965. During this time, LTJG Shankel made two combat deployments to Southeast Asia from August 1964 to May 1965, and again from October 1965 until he was shot down in December 1965. After spending 2,609 days in captivity, LCDR Shankel was released during Operation Homecoming on February 12, 1973. He was briefly hospitalized to recover from his injuries at the U.S. Naval Hospital in Oakland, California, and then attended the University of Connecticut, receiving his Bachelor's degree in June 1976, followed by the University of Connecticut School of Medicine, where he received his Doctor of Medicine degree in February 1979. CDR Shankel next completed his Internship and Residency at NNMC Bethesda, Maryland, in July 1984, and retired from the Navy on April 1, 1985. He is a Board Certified Surgeon.

His Silver Star Citation reads:

For conspicuous gallantry and intrepidity while interned as a Prisoner of War in North Vietnam. In December 1965, his captors, completely ignoring international agreements, subjected him to extreme mental and physical cruelties in an attempt to obtain military information and false confessions for propaganda purposes. Through his resistance to those brutalities, he contributed significantly toward the eventual abandonment of harsh treatment by the North Vietnamese, which was attracting international attention. By his determination, courage, resourcefulness, and devotion to duty, he reflected great credit upon himself and upheld the highest traditions of the Naval Service and the United States Armed Forces.