Before World War II, Oklahoma City developed major stockyards, attracting jobs and revenue formerly in Chicago and Omaha, Nebraska. With the <answer>1928</answer> discovery of oil within the city limits (including under the State Capitol), Oklahoma City became a major center of oil production. Post-war growth accompanied the construction of the Interstate Highway System, which made Oklahoma City a major interchange as the convergence of I-35, I-40 and I-44. It was also aided by federal development of Tinker Air Force Base.
When was oil discovered in the city limits?
1928