Rufus was born on the 7th of June 1874, in Licolnton, North Carolina, and not much is known about his life. His father was a Presbyterian minister and Rufus received an appointment to the US Naval Academy, graduating with the class of 1895. He was deployed to Cuba, where he took part in the Battle of Santiago de Cuba (a battle in the Spanish-American War), as well as to China during the Boxer Rebellion, and to the Philippines during the Philippine-American War. By the time he deployed to Mexico, he was a Lieutenant Commander, and it was his actions there that would later earn him the Medal of Honor. The citation reads:

For distinguished conduct in battle, engagement of Vera Cruz, 22 April 1914; was regimental adjutant, and eminent and conspicuous in his conduct. He exhibited courage and skill in leading his men through the action of the 22d and in the final occupation of the city.

Rufus received the Medal of Honor on the 4th of December 1915, and went on to serve in World War 1. He retired as a Rear Admiral in 1930 and he was married to Emma Pegram, with whom the couple had two children. Rufus Zenas Johnston died on the 4th of July 1959, at the age of 85, and he and his wife are buried in Arlington National Cemetery: Section 2, Grave 3645.