Headquarters for Amoco Corporation were in Chicago, because that city is close to Whiting, Indiana. Whiting was home of Amoco’s largest oil refinery (and one of the largest in the world). In operation since 1890, Whiting originally refined sour crude oil from the neighbouring state of Ohio. And it was Standard of Indiana's (Amoco's) most important single asset after the US Supreme Court ordered the Standard Oil Trust broken up. In its early years, Amoco was primarily a refiner and a marketer of refined products to expanding Midwestern markets. Whiting provided products that could be marketed from Chicago — a city that was itself a large market for petroleum products.