Iowa native H. H. Henningson wanted to lift small communities from their frontier status through civil engineering. His dream became reality in 1917 when he founded Henningson Engineering Company. The employee-owned firm has since blossomed into one of the largest and most respected architecture-engineering companies.
HDR stands for the initials of founders H.H. Henningson, Charles Durham and Willard Richardson. Henningson Engineering Company officially became Henningson, Durham & Richardson, Inc. in 1950. The name was later shortened to HDR, Inc.