'Interstate Tractor Co. ran into financial difficulty in 1918, eventually becoming Plowman Tractor Co., and remaining in Waterloo. Shortly after this 1919 advertisement, the company disappeared, as did Plowboy and Plowman tractors. '
The Plow Man 13-30 was one of Interstate Engine & Tractor Co.’s first machines. It had a Buda 4-cylinder engine with 4-1/4-by-5-1/2-inch bore and stroke. The later 15-30 was almost identical in appearance.
'A 1919 ad for Plowman Tractor Co., the third of three companies that manufactured Plowboy and Plowman tractors. In this ad, the name of the tractor, Plowman, was not broken into two words as in earlier ads. '
'A Plow Man tractor, manufactured by Interstate Tractor Co., is shown working a field in this undated photo. '