1. On September 21, 1907, Oklahoma became the 46th state to be admitted into the Union. This day is celebrated as Oklahoma Statehood Day.

2. The September 21, 1974 football game between Oklahoma and Baylor was one of the highest-scoring games in college football history. The final score was Oklahoma 77, Baylor 7.

3. On September 21, 1923, the largest parade in Tulsa history took place. The parade was held to celebrate the opening of the oil and gas industry in Oklahoma.

4. The Oklahoma Department of Corrections opened its first prison on September 21, 1973. The facility was located in McAlester and had a capacity of 756 inmates.

5. The Cherokee Outlet, which was a large tract of land in northern Oklahoma, was opened to settlement on September 21, 1893. This event is known as the Cherokee Strip Land Run and resulted in the settlement of over 100,000 people in a single day.