John graduated from Monroe High School in 1962 and received his Bachelor of Architecture degree from the University of Michigan in 1967.

John was a registered Architect in Michigan and Ohio and began his 47-year architectural career working for Richards, Bauer and Moorehead in Toledo, OH, and D.H. Dunbar in Monroe, MI, before establishing the architectural firm John D. Kohler Architect, P.C. in 1977, which he operated for 37 years before passing this legacy on to his sons Mark and Keith.

An avid fisherman, John spent his summers on Lake Erie chasing walleye and perch, and enjoying friends and family. He also enjoyed hunting, shooting trap, and tinkering around his home on the lake.

An involved member of the Monroe community, John served on the Fine Arts Council for over 40 years and was heavily involved in the Monroe County Student Design Competition. He was an honorary life member of the Monroe Exchange Club, life member of the Monroe County Rod and Gun Club, and past board member of Mercy Memorial Hospital.