John Coons was born in 1828 or 1829 in Knox County Indiana, and was a lawyer in Vincennes before the war.

On June 7, 1861 he became Captain of Company G of the 14th Indiana Infantry. He was wounded at Antietam on September 17, 1862, but returned to his regiment and was eventually promoted to colonel, commanding the regiment at Gettysburg.

Colonel Coons was killed on May 12, 1864 at Spottsylvania Court House.