He received the award for his actions on April 1, 1970, while serving in Tây Ninh Province during the Vietnam War.

Lemon is the only Canadian-born United States citizen to be presented the medal for fighting in the Vietnam War.

His book and documentary have been donated to every high school in the United States to inspire American children "to be worthy citizens.

"[3][4] Lemon has also run several corporations, including American Hospitality Association, Inc.; Darnell-Lemon, Inc.; and Probus, Inc. On May 1, 2009, Lemon was presented with the "Outstanding American by Choice" award by President Barack Obama at the White House, recognizing his life of professional achievement and civic contribution.

[5] A marble tribute honoring Lemon is present in Veteran's Park in Tawas City, Michigan.

Lemon (then Sp4), Company E, distinguished himself while serving as an assistant machine gunner during the defense of Fire Support Base Illingworth.

Lemon engaged a numerically superior enemy with machine gun and rifle fire from his defensive position until both weapons malfunctioned.

Lemon's gallantry and extraordinary heroism, above and beyond the call of duty, are in keeping with the highest traditions of the military service and reflect great credit on him, his unit, and the U.S.