Peter was born on the 5th of June 1950, in Toronto, Canada, and he emigrated to the United States on the 16th of April 1952, through Port Huron, Michigan. He grew up near Tawas City, Michigan, where he graduated from high school in 1968, before enlisting in the US Army shortly after high school. Peter was a squad leader when he arrived in the Republic of Vietnam in July of 1969, and many of the beliefs that were paramount to him joining the military soon went away once he witnessed the realities of the war. This led Peter and many others to not be sober while on duty as a way of coping with this reality and even though it was illegal to smoke marijuana, Peter and some others took to smoking before bed. This was the case after a patrol on the 31st of March 1970, and Peter awoke, high, to an attack on Fire Base Illingworth. It was his actions when the base was attacked, with the Americans being outnumbered two to one, that would later earn him the Medal of Honor. The citation reads:

For conspicuous gallantry and intrepidity in action at the risk of his life above and beyond the call of duty. Sgt. Lemon (then Sp4c.), Company E, distinguished himself while serving as an assistant machine gunner during the defense of Fire Support Base Illingworth. When the base came under heavy enemy attack, Sgt. Lemon engaged a numerically superior enemy with machine-gun and rifle fire from his defensive position until both weapons malfunctioned. He then used hand grenades to fend off the intensified enemy attack launched in his direction. After eliminating all but one of the enemy soldiers in the immediate vicinity, he pursued and disposed of the remaining soldier in hand-to-hand combat. Despite fragment wounds from an exploding grenade, Sgt. Lemon regained his position, carried a more seriously wounded comrade to an aid station, and, as he returned, was wounded a second time by enemy fire. Disregarding his personal injuries, he moved to his position through a hail of small-arms and grenade fire. Sgt. Lemon immediately realized that the defensive sector was in danger of being overrun by the enemy and unhesitatingly assaulted the enemy soldiers by throwing hand grenades and engaging in hand-to-hand combat. He was wounded yet a third time, but his determined efforts successfully drove the enemy from the position. Securing an operable machine gun, Sgt. Lemon stood atop an embankment fully exposed to enemy fire, and placed effective fire upon the enemy until he collapsed from his multiple wounds and exhaustion. After regaining consciousness at the aid station, he refused medical evacuation until his more seriously wounded comrades had been evacuated. Sgt. Lemon's gallantry and extraordinary heroism are in keeping with the highest traditions of the military service and reflect great credit on him, his unit, and the U.S. Army.

Peter received the Medal of Honor from President Nixon on the 15th of June 1971, in a ceremony at the White House, becoming one of forty Canadian-born recipients. He left the Army the following year at the rank of Sergeant and went on to graduate from Colorado State University in 1979. Peter received his master’s degree from the University of Northern Colorado two years later and it wasn’t until the early 1990s that he accepted the responsibility of wearing the Medal of Honor. In 1997, he wrote “Beyond the Medal: A Journey from Their Hearts to Yours”, a compilation of stories, personal thoughts and feelings of the country’s Medal of Honor recipients. This was also turned into a documentary of the same name by PBS with Peter being an executive producer. He married and with his wife had three children. Peter Charles Lemon is 72 years old at the time of writing, and he still tours as a motivational keynote speaker, residing in Colorado.