John DeCew (1766–1855), (variably spelt DeCou, Du Coo or DeCow, and sometimes with the "C" not capitalized) was a United Empire Loyalist, an early settler in the Niagara Peninsula of Upper Canada, a commissioned militia officer in the War of 1812, and a founding member of the Welland Canal Company.
He was captured by American forces in May, 1813, while returning home following the British defeat at the Battle of Fort George and incarcerated in Philadelphia, Pennsylvania.
He escaped from his captivity in April, 1814, and returned to Niagara to take part in the remainder of the war, including the Battle of Lundy's Lane.
It was to here that Laura Secord journeyed to warn the officer in charge, James Fitzgibbon, of the American advance prior to the Battle of Beaver Dams.
[1][4] In 1832, DeCew unsuccessfully opposed William Hamilton Merritt's bid for election to the Legislative Assembly of Upper Canada in what has been described as an extremely vindictive campaign.
He failed to secure rights to operate a bridge or ferry on the Grand River, but in 1835 did obtain an incorporation for a glass works.
DeCew lived off of his milling, farming and lime kiln operations, and died in Decewsville, Ontario (a settlement named in his honour) on March 25, 1855.