Besides being a respected medical practitioner in his own city, Hamilton became a Fellow of the American College of Surgeons in 1920, president of the Manitoba Medical Association in 1921-22 and founder and first editor of the "Manitoba Medical Bulletin", and president of the Canadian Medical Association in 1922. He was an elder of King Memorial church for 28 years. T.G. served on the Public School Board for nine years from 1906 to 1915, one year as chairman. T.G. was the first president of the University of Manitoba Alumni Association in 1921 and became the first president of the Winnipeg Society for Psychical Research in 1931.