I heard one reason that why Canadian Pacific & Canadian National started buying up American railroads was that they were getting tired of dealing with the strikes at several of the port facilities at Thunder Bay. With the line to Vancouver getting clogged with rail traffic, CP & CN bought lines in the States so they could their products to port easier & quicker.
Any truth to this & is there more?
Not likely to be true, both CP and CN had ownership stakes in US railroads dating back to the 19th Century. The very first line built by CP proper ran from Winnipeg, to Emerson, MB right on the US border to bring in supplies to build the railroad. The Grand Trunk Western was an extension of the original mainline of the Grand Trunk the first built part of what is now CN. Thunder Bay was an important shipping port for Grain, and Iron Ore, and more recently coal. The Iron Ore mines have closed in western Ontario so no Iron Ore is shipped through Thunder Bay, and Ontario Hydro no longer burns Lignite coal from the fields in southern Saskatchewan, instead buy higher grade PRB coal to supplement the eastern US bituminous that they have always used. In season both railroads still move grain to the port of Thunder Bay, but grain moving east in both the US and Canada is way down from past amounts as Europe buys more grain from South America. Most of the products moved by CN and CP from western Canada to the US never moved via Great Lakes shipping except a small amount of grain.