Agnes Miller was born 11 April 1859 at Truro, N.S., the daughter of Alexander and Sarah (Archibald) Miller. She attended Truro's Model and Normal Schools and taught at the Model School for two years prior to her marriage in 1878 to William Dennis, later owner and publisher of the Halifax Herald and senator. The couple had four sons and six daughters. Dennis began her public work in 1903, serving as president of the Halifax Victorian Order of Nurses for forty-three years. She was also a charter member and president of the Halifax Local Council of Women, 1905-1920, and executive member of its national council. Through the LCW, she assisted in organizing the Nova Scotia Provincial Red Cross Society and served as president, 1914-1920. Other organizations in which she actively participated include the Women's Auxiliary, YMCA 1910-1921, Halifax Relief Committee, Canadian Council of Immigration of Women, and Nova Scotia Provincial Girl Guides. She was also president of Halifax Herald Limited. Dennis received several national and international awards for her achievements including the Belgian Order of Queen Elizabeth (1919), Commander of the British Empire (CBE, 1934), King's Silver Jubilee Medal (1935) and honourary degrees from Acadia (MA, 1920) and Dalhousie (LLD, 1940). She died at Halifax on 21 April 1947.