The sacking of York was a primary motivation for the Burning of Washington by British troops later in the war. York was incorporated as the City of Toronto on March 6, 1834, reverting to its original native name. The population of only 9,000 included escaped African American slaves. Slavery was banned outright in Upper Canada in 1834. Reformist politician William Lyon Mackenzie became the first Mayor of Toronto and led the unsuccessful Upper Canada Rebellion of 1837 against the British colonial government. The city grew rapidly through the remainder of the 19th century, as a major destination for immigrants to Canada. The first significant population influx occurred with the Great Irish Famine brought a large number of Irish to the city, some of them transient and most of them Catholic. By 1851, the Irish-born population had become the largest single ethnic group in the city. Smaller numbers of Protestant Irish immigrants were welcomed by the existing Scottish and English population, giving the Orange Order significant and long lasting influence over Toronto society.
Toronto was twice for brief periods the capital of the united Province of Canada: first from 1849 to 1852, following unrest in Montreal, and later 1856–1858 after which Quebec became capital until 1866 (one year before Confederation); since then, the capital of Canada has remained Ottawa. As it had been for Upper Canada from 1793, Toronto became the capital of the province of Ontario after its official creation in 1867, the seat of government located at the Ontario Legislature located at Queen's Park. Because of its provincial capital status, the city was also the location of Government House, the residence of the vice-regal representative of the Crown.
In the 19th century, an extensive sewage system was built, and streets became illuminated with gas lighting as a regular service. Long-distance railway lines were constructed, including a route completed in 1854 linking Toronto with the
