The Case Corporation was a manufacturer of construction equipment and agricultural equipment. Founded by Jerome I. Case as the J.I. Case Threshing Machine Company, it operated under that name for most of a century. For another 66 years it was the J.I. Case Company, and was often called simply Case. In the late 19th century, Case was one of America’s largest builders of steam engines, producing self-propelled portable engines, traction engines and steam tractors. It was a major producer of threshing machines and other harvesting equipment. In the 20th century, Case was among the 10 largest builders of farm tractors for many years. In the 1950s its construction equipment line became its primary focus, with agricultural business second.