group of about 7,000 United Empire Loyalists were thinly settled across the province in the mid-1780s, a far larger number of "late-Loyalists" arrived in the late 1790s and were required to take an oath of allegiance to the Crown to obtain land if they came from the US. Their fundamental political allegiances were always considered dubious. By 1812, this had become acutely problematic since the American settlers outnumbered the original Loyalists by more than ten to one. Following the War of 1812, the colonial government under Lt. Governor Gore took active steps to prevent Americans from swearing allegiance, thereby making them ineligible to obtain land grants. The tensions between the Loyalists and late Loyalists erupted in the "Alien Question" crisis in 1820–21 when the Bidwells (Barnabas and his son Marshall) sought election to the provincial assembly. They faced opponents who claimed they could not hold elective office because of their American citizenship. If the Bidwells were aliens so were the majority of the province. The issue was not resolved until 1828 when the Colonial government retroactively granted them citizenship. Freed slaves The Act Against Slavery passed in Upper Canada on 9 July 1793. The 1793 "Act against Slavery" forbade the importation of any additional slaves and freed children. It did not grant freedom to adult slaves—they were finally freed by the British Parliament in 1833. As a consequence, many Canadian slaves fled south to New England and New York, where slavery was no longer legal. Many American slaves who had escaped from the South via the Underground Railroad or fleeing from the Black Codes in the Ohio Valley came north to Ontario, a good portion settling on land lots and began farming. It is estimated that thousands of escaped slaves entered Upper Canada from the United States. British The Great Migration from Britain from 1815 to 1850 has been numbered at 800,000. The population of Upper Canada in 1837 is documented at 409,000. Given the lack of detailed census data, it is difficult to assess the relative size of the American and Canadian born "British" and the foreign-born "British." By the time of the first census in 1841, only half of the population of Upper Canada were foreign-born British. Irish Scottish English Religion Church of England The first Lt. Governor, Sir John Graves Simcoe, sought to make the Church of England the Established Church of the province. To that end,