Civil War officer. Son of Governor Paul Dillingham. Brother of Governor and Senator William Dillingham. Attended local schools. Married Charlotte (Lottie) Parker. Two children, Elizabeth and Charles. Studied law with brother in law Matthew Carpenter who was later elected to US Senate from Wisconsin. Attended law school in Poughkeepsie, New York and graduated in 1859. Admitted to bar, commenced practice in Waterbury, September, 1860. Enlisted for Civil War, 1862. Took part in recruiting Company B, 10th Vermont Volunteer Infantry, which he commanded after he was commissioned as a captain. Taken prisoner at battle of Locust Grove, 1863. Prisoner at Libby, 1863-64. Paroled and rejoined regiment at Cold Harbor, June 1864. Temporarily commanded at Cold Harbor a battalion of paroled prisoners returning to duty. Commissioned major and appointed regimental commander, June 17, 1864. Killed in battle while commanding his regiment. Grand Army of the Republic post in Waterbury was named for him.