Does anyone know what the forerunner to the Oliver tractor is?

I have no idea what the name of the forerunner to the Oliver tractor is but I remember my grandfather telling me that before the gas powered tractors were used some farmers used a locomotive type steam traction engine. Not sure this answers the question but it's all I remember. Of course, I suppose if I looked it up I could find the correct answer. My grandfather was a farmer in Maine but had also worked in Washington State in the lumber business which if member serves me right was the first commercial use of the steam "tractor".