The most important economic activity in Ontario is manufacturing, and the Toronto–Hamilton region is the country's most highly industrialized area.
The area from Oshawa, Ontario around the west end of Lake Ontario to Niagara Falls, with Hamilton at its centre, is known as the Golden Horseshoe and had a population of approximately 8.1 million people in 2006.
The phrase was first used by Westinghouse President Herbert H. Rogge in a speech to the Hamilton Chamber of Commerce, on January 12, 1954. "
Hamilton in 50 years will be the forward cleat in a golden horseshoe of industrial development from Oshawa to the Niagara River ... 150 miles long and 50 miles (80 km) wide...It will run from Niagara Falls on the south to about Oshawa on the north and take in numerous cities and towns already there, including Hamilton and Toronto."

With sixty percent of Canada's steel produced in Hamilton by Stelco and Dofasco, the city has become known as the Steel Capital of Canada.
After nearly declaring bankruptcy, Stelco returned to profitability in 2004.
On August 26, 2007 United States Steel Corporation acquired Stelco for C$38.50 in cash per share, owning more than 76 percent of Stelco's outstanding shares.
On September 17, 2014, US Steel Canada announced it was applying for bankruptcy protection and it would close its Hamilton operations.

A stand-alone subsidiary of Arcelor Mittal, the world's largest steel producer, Dofasco produces products for the automotive, construction, energy, manufacturing, pipe and tube, appliance, packaging, and steel distribution industries.
It has approximately 7,300 employees at its Hamilton plant, and the four million tons of steel it produces each year is about 30% of Canada's flat-rolled sheet steel shipments.
Dofasco was North America's most profitable steel producer in 1999, the most profitable in Canada in 2000, and a long-time member of the Dow Jones Sustainability World Index.
Ordered by the U.S. Department of Justice to divest itself of the Canadian company, Arcelor Mittal has been allowed to retain Dofasco provided it sells several of its American assets.
The most important economic activity in Ontario is manufacturing, and the Toronto–Hamilton region is the country's most highly industrialized area. The area from Oshawa, Ontario around the west end of Lake Ontario to Niagara Falls, with Hamilton at its centre, is known as the Golden Horseshoe and had a population of approximately 8.1 million people in 2006. The phrase was first used by Westinghouse President Herbert H. Rogge in a speech to the Hamilton Chamber of Commerce, on January 12, 1954. "Hamilton in 50 years will be the forward cleat in a golden horseshoe of industrial development from Oshawa to the Niagara River ... 150 miles long and 50 miles (80 km) wide...It will run from Niagara Falls on the south to about Oshawa on the north and take in numerous cities and towns already there, including Hamilton and Toronto."
With sixty percent of Canada's steel produced in Hamilton by Stelco and Dofasco, the city has become known as the Steel Capital of Canada. After nearly declaring bankruptcy, Stelco returned to profitability in 2004. On August 26, 2007 United States Steel Corporation acquired Stelco for C$38.50 in cash per share, owning more than 76 percent of Stelco's outstanding shares. On September 17, 2014, US Steel Canada announced it was applying for bankruptcy protection and it would close its Hamilton operations. 
A stand-alone subsidiary of Arcelor Mittal, the world's largest steel producer, Dofasco produces products for the automotive, construction, energy, manufacturing, pipe and tube, appliance, packaging, and steel distribution industries. It has approximately 7,300 employees at its Hamilton plant, and the four million tons of steel it produces each year is about 30% of Canada's flat-rolled sheet steel shipments. Dofasco was North America's most profitable steel producer in 1999, the most profitable in Canada in 2000, and a long-time member of the Dow Jones Sustainability World Index. Ordered by the U.S. Department of Justice to divest itself of the Canadian company, Arcelor Mittal has been allowed to retain Dofasco provided it sells several of its American assets.
Hamilton, Ontario