High Quality Content by WIKIPEDIA articles! The Constitutional Act of 1791 was an Act of the Parliament of Great Britain (1791 (31 Geo. 3) C A P. XXXI., long title An Act to repeal certain Parts of an Act, passed in the fourteenth Year of his Majesty's Reign, intituled, An Act for making more effectual Provision for the Government of the Province of Quebec, in North America; and to make further Provision for the Government of the said Province.) which changed the government of the province of Quebec to accommodate the many English-speaking settlers, known as the United Empire Loyalists, who had arrived from the United States following the American Revolution. Quebec was divided in two when the act took effect on December 26, 1791. The western half became Upper Canada (now southern Ontario) and the eastern half Lower Canada (now southern Quebec). The names Upper and Lower Canada were given according to their location on the St. Lawrence River, as opposed to geographical location.