Starting in 1883, CPR began using the O&Q to build a network in southern Ontario to compete with the Grand Trunk Railway. The O&Q leased the Credit Valley Railway, Toronto Grey & Bruce, London Junction Railway and some sections of the Canada Southern Railway, building an extensive portfolio of routes. In August 1888 they provided a direct through route to Montreal by leasing the Atlantic and North-west Railway and connecting it to the O&Q via an extension from Smiths Falls to the Quebec border. A final major extension was the West Ontario Pacific Railway (WORP), which connected the Credit Valley in Woodstock to Windsor and the US border. The WOPR opened in 1887, and was immediately leased to the O&Q.