During the First World War, in 1917, Mimico became fully independent and elected its first Mayor, John Harrison, by acclamation. The town also reacted to the sensational execution of British Nurse Edith Cavell by naming Mimico's old Southampton Street in her memory in 1916. Another street was also given this name in Toronto's East End leading to recent attempts by Toronto to rename Mimico's Cavell Ave. At the end of the war, the local chapter of the Imperial Order of the Daughters of the Empire, who met at the Carnegie Library, presented the town with two plaques honouring all those from the town who had enlisted and another honouring those who had died.