Northern Kansas contains the geographic center of the contiguous United States. The state has many nicknames including the Wheat State, Sunflower State, and Jayhawk State. In Kansas’ early years, the economy relied heavily on farming its rich soil. Wheat production first came to the state in the late 1800s and remained at the core of the economy until the 1940s. Though agriculture is not the leading component of the economy anymore, Kansas remains the leading wheat producer in the nation. During World War II, Kansas witnessed a large increase in manufacturing activities as the federal government moved war industries away from coastal areas. The largest contributor to the Kansas economy is now transport manufacturing, especially the production of aircraft and aircraft parts.