The Easy windmill was manufactured by the Easy Manufacturing Company of Lincoln, Nebraska.  At least as early as the mid-1920's, the Easy Manufacturing Company was producing open back geared and then later oil bath back geared steel pumping windmills from a plant located at 1405 North 12th Street in Lincoln, Nebraska.  Owned by father and son, John F. and Charles D. Ammon, the firm produced a range of farm implements including its windmills.  The Ammons purchased castings from a neighboring firm across the street, the Cushman Motor Works, which at the time was best known for its internal combustion engines.  The Ammon family at Easy Manufacturing Company not only distributed their windmills under there own trade names as Easy Mills, but they also supplied them under contract to Montgomery Ward and Company, which for a decade sold them through its mail order catalogs as Air King Windmills.  Today these mills may be seen in the field under both names. 
The Ammon family became interested in the nearby Cushman manufacturing plant, and John Ammon quietly began purchasing Cushman stock.  By 1934, he had gained a controlling interest in the Cushman firm and merged it with the Easy Company under the Cushman name with his son Charles installed as CEO. 
For several more years, the Cushman Motor works continued to produce the Easy windmills, although the firm devoted most of its efforts to manufacturing a new and increasingly popular product, the Cushman motor scooter.