Oklahoma’s Silver Jubilee – its 50th anniversary of statehood – was honored on U.S. #1092. The stamp was issued in conjunction with Oklahoma’s Semi-Centennial Exposition, which ran from April 22 to November 16 of that year. April 22 marked the anniversary of the first Oklahoma “land run.” In 1889, an estimated 50,000 people lined up on the borders of the territory for the chance to race in and stake out free ground. Some people sneaked over the boundary before the start, in order to get to their chosen area “sooner” – a term which would become the nickname of the state. The final day of the exposition coincided with the 50th anniversary of statehood. The phrase “From Arrows to Atoms” runs across the top of the stamp. It reflects Oklahoma’s evolution from the frontier days before statehood to the new frontiers expressed by atomic energy during the 1950s.