DeKalb began in 1912 when farmers and bankers organized the DeKalb County Soil Improvement Association to improve local farming, and in 1917 the DeKalb County Agricultural Association emerged from it with an emphasis on quality seed. Hybrid corn research started in 1924, and by 1940 DeKalb led the nation in hybrid seed corn sales, with the winged ear logo becoming its international trademark. The company extended hybridization to sorghum, sunflowers, egg-laying poultry, and swine breeding stock, and also added varietal alfalfa and soybean seed. It later diversified into oil and gas exploration and other agriculture- and oil-related businesses, then by 1988 returned to its core business as a global leader in agricultural genetics for seed, swine, and poultry. DeKalb was recognized as the first company to patent transgenic corn and later introduced genes giving farmers herbicide, pest, and disease resistance. An equal profit-sharing plan for full-time employees and substantial charitable giving through its foundation also marked the company. Its original headquarters were on Fifth Street before moving to this location in 1966. In 1970 DeKalb went public with voting and non-voting share classes, while the Roberts family kept majority ownership of the voting shares. Its stock traded on NASDAQ and later on the NYSE, until Monsanto Company completed its purchase of DeKalb in 1998 at a total valuation of $3.7 billion. Bayer AG purchased Monsanto in 2018, and DeKalb brand seed products continue to be developed and distributed worldwide.