Municipal Boundaries

Look in the Statutes of Ontario ( DBW govt J 108.K6S73) in the index see: Act of Incorporation. 

Example:  Regional Municipality of Haldimand - Norfolk Act, Statutes of Ontario, 1973, C. 96 (DBW govt J 108.K6 S73)
City of Thunder Bay Act, 1968-69, Statutes of Ontario, 1968 - 69, C. 56 (DBW govt J 108.K6 S73)
Municipality of Metropolitan Toronto Act, Revised Statutes of Ontario, 1970, C. 295 (DBW govt J 108.K6R48)

Changes to Municipal Boundaries, Status and Names (1975 - 1985) DBW govt HA 748.9.A2 12-C201 and DBW govt HA 748.9.A2 12-C549

Planning Profile:  Planning Area, Official Plan, Zoning, Committee of Adjustment, Land Division Committee, Former Municipality (1973 - 1980) DBW govt JL 272.9.H68P63

Ward Maps for London 1854-1950 ARCC C292