John Florhaug was born on August 6, 1893 in Norway. He was the son of Paul Paulsen and Ingeborg Johnson Trĝan Florhaug. He came to the Kensal area in 1915 with his parents Paul and Ingeborg Florhaug. He farmed with his father until he enlisted in the Army during World War I in the fall of 1917.

He was sent to Camp Mills on October 3, 1917 and left for France on December 12, 1917. He served in the U.S. Army during World War I as a Private in Machine Gun Company, 28th Infantry Regiment, 1st Infantry Division. He was wounded on August 22, 1918 and spent three weeks in a hospital. He returned to his company and was killed in action on October 4, 1918. He is now buried in Kensal Cemetery, Kensal, Stutsman County, North Dakota, USA.

The Kensal American Legion Post is named for John Florhaug. His name is commemorated on the First Infantry Division monument in Saint-Juvin, France but his surname is inscribed as Florhang.