1. Oklahoma becomes a state: On September 16, 1907, Oklahoma officially became the 46th state of the United States. The statehood ceremony took place in the new state capital of Oklahoma City, with President Theodore Roosevelt in attendance.

2. Oklahoma City bombing trial begins: On September 16, 1997, the trial of Timothy McVeigh began in Denver, Colorado. McVeigh was convicted of the bombing of the Alfred P. Murrah Federal Building in Oklahoma City on April 19, 1995, which killed 168 people and injured hundreds more.

3. Native American Day: In Oklahoma, September 16 is recognized as Native American Day, a day to honor and celebrate the contributions of the state's indigenous people. Many events and activities take place across the state to mark the occasion.

4. Tulsa Race Massacre Commission established: On September 16, 2020, Oklahoma Governor Kevin Stitt signed an executive order establishing the Tulsa Race Massacre Commission. The commission's mission is to investigate and recommend solutions for reparations to the survivors and descendants of the 1921 Tulsa Race Massacre, in which a white mob destroyed the thriving Black community of Greenwood.

5. Oklahoma State Fair opens: In recent years, the Oklahoma State Fair has typically opened on or around September 16. The fair, which dates back to 1907, features exhibitions, livestock shows, carnival rides, and a variety of food and entertainment options.