The Waterloo Gasoline Company began business in 1893 and started engine production in 1895. In 1906, the company began production of its "Waterloo Boy" hopper-cooled open crank engine that characterized its well-known line for the next fifteen years. During this time, Waterloo became one of the “big four” manufacturers along with Fairbanks Morse, Hercules and International Harvester. From 1906 through 1918, Waterloo engines were sold by at least sixty-four companies with each having their own ID tag attached. The Majestic, Eaton, John Smyth, Jackson, Sandow and Waterloo Boy are some of the more common Waterloo engines.

After the sale of Waterloo to Deere and Company in March of 1918, the company introduced a new design with the "H” gasoline and “K” kerosene models with drip oiler relocated to hopper top and other mechanical changes. Production of the “H” model seems to have started in mid-1919 (#201476 is the earliest found) and ceased in 1925 (#240973 is latest found). Production of the “K” model seems to have started in mid-1919 (#160187 is the earliest found) and ceased in late 1921 (#222845 is the latest found). Production of the Deere type "E" began in 1921 (#200065 is the earliest found) and ended in 1946. A “Waterloo Boy Repairs and Parts List No.10” dated April 1, 1920 and “No. 11” dated July 15, 1920 for the “K” model have been found indicating production probably began in mid-1919. Information on “H”, “K” and “E” model engines with serial numbers before or after these listed is sought to aid in our research.

The Deere and Company Collectors Center has provided the following list of serial numbers for the "Waterloo Boy" engines. Serial numbers are located on the I. D. tag and on the end of the crankshaft on igniter side. A few of the companies selling Waterloo engines added a letter in front of their serial numbers. Production in most, if not all, years was seven days each week. The beginning number in January for each year is listed.