Mayo Blackburn was born on August 19, 1922, in Huddy, Pike County, Kentucky. He was the son of Ellis Blackburn and Mariah Varney Blackburn. He was married to Edith Lyle "Edie" Bevins.

He served in Company A, 1st Battalion, 22nd Marine Regiment, 1st Provisional Marine Brigade as a Corporal during World War II. He was Killed in Action on July 25, 1944, during the Battle for Guam.

Posthumous Silver Star Citation:
The President of the United States of America takes pride in presenting the Silver Star (Posthumously) to Corporal Mayo Blackburn (MCSN: 405782), United States Marine Corps, for conspicuous gallantry and intrepidity while in command of a Combat Group serving with the First Battalion, Twenty-Second Marines, First Provisional Marine Brigade, during an attack on an enemy Japanese-held ridge near Orote Peninsula on Guam, Marianas Islands, 25 July 1944. With the advance of his company threatened by extremely heavy fire from cleverly concealed positions of the enemy, Corporal Blackburn courageously risked his life to move forward and locate the hidden emplacement. Returning to his group, he quickly brought up the mortar forward observers and directed vigorous fire against the Japanese emplacements and, although mortally wounded during the action, refused to be evacuated until the mission was successfully completed. His exceptional fortitude, valiant initiative and unwavering devotion to duty at great peril to himself reflect the highest credit upon Corporal Blackburn and the United States Naval Service. He gallantly gave his life for his country.