The firm has a long and distinguished history. It began in 1885 when William C. Dowler began his legal practice in the Town of Tillsonburg. He was joined by Victor Sinclair in the early 1890s. Mr. Dowler continued to practice until approximately 1910. Mr. Sinclair continued to practice alone until 1925 when he was joined by Donald F. Gibson, upon the latter's graduation from Osgoode Hall Law School. They practiced together until the late 1920s when Mr. Sinclair moved to Toronto and became the first chairman of what is now known as the Workplace Safety & Insurance Board.

Donald F. Gibson continued to practice alone for many years. During that time he was the Mayor of the Town of Tillsonburg and actively involved in the community. In the mid 1930s he was joined by Robert Glenn Groom who became the Provincial Magistrate for the County of Oxford shortly after World War II.  Mr. Groom was in partnership with various lawyers over the years including Bill Weir, Olie Mandryk and Michael Szorenyi.  Donald F. Gibson continued to practice alone until 1954 when his son, Donald M. Gibson joined him in practice. Unfortunately, Donald F. Gibson died in 1955. In 1956 Ian R. Linton joined the firm and they practiced together until 1963 when Bernard Toth amalgamated his sole practice with the Gibson, Linton partnership. Ian Linton passed away in 2001.  Scott K. Campbell joined the firm in 1978. Scott Campbell was appointed a Superior Court Justice in July, 2009. Donald M. Gibson retired from practice in 1993. D. Bradley Bennett began to practice with the firm in 1995.  In 2009, Gibson, Linton, Toth, Campbell and Bennett merged with Groom and Szorenyi to create the firm Gibson Bennett Groom & Szorenyi.