Cooperative Grain and Supply was formed on May 1, 1966 through the merger of four local cooperatives in Hillsboro, Lehigh, and Marion. Since then, CG&S has expanded through additions such as the Canton Coop, Canada Grain, Ampride stations, the Canton Service Center, the Canton CStore, and the Hillsboro Hoop Grain Facility. In 2023, the Hillsboro Crop Production facility also completed a major liquid fertilizer plant expansion.

Over the years, CG&S has grown its grain storage capacity from 1.2 million bushels to more than 6.3 million bushels and has built partnerships through ventures including Countryside Feed, LLC, Co-Ag Propane, LLC, CoMark Equity Alliance, LLC, and Smoky Hill Terminal.