Canadian journalist William Lyon Mackenzie (1795-1861), strongly advocating a republican form of government for Upper Canada (Ontario), called for the overthrow of the British-dominated ruling clique, the Family Compact. About 800 followers of Mackenzie tried but failed to establish a provisional government at Toronto and were forced to flee to Navy Island on the Niagara River. There Mackenzie proclaimed a government. After Canadians loyal to the Upper Canada government crossed the river and burned the US steamer Caroline, which had been carrying supplies to the Mackenzie's rebels, Mackenzie abandoned Navy Island and fled to the United States, where he was imprisoned for 11 months for violating the neutrality laws. Later, under a proclaimed general amnesty, he returned to Canada in 1849.