In 1891, Massey merged with the A. Harris, Son & Co. Ltd. to become Massey-Harris Co. and became the largest agricultural equipment maker in the British Empire. In 1910, the company opened a factory in the United States, making it one of Canada’s first multinational firms.

The Massey-Harris Company decided that they needed a tractor in their range, so in 1917, they introduced Bull tractors built in the U.S. and branded them as Massey-Harris for the Canadian market. When in 1919 the Bull Tractor Co. failed, Massey-Harris then sold tractors based on Parrett designs that were built over the border in Chicago.