1. On March 21, 1907, the first State Capitol building in Oklahoma was completed. The building, located in Guthrie, served as the state capital until 1910 when the capital was moved to Oklahoma City.

2. In 1935, on March 21, Will Rogers, the famous American humorist and actor, was inducted into the Oklahoma Hall of Fame. Rogers was born in Indian Territory, which later became part of the state of Oklahoma, and he often used his Oklahoma background and experiences in his comedy routines.

3. On March 21, 1937, the famous Cherokee Indian actor, Wes Studi, was born in Nofire Hollow, Oklahoma. Studi is known for his roles in movies such as "Dances with Wolves", "The Last of the Mohicans", and "Avatar". Studi has also been an activist for Native American causes and has been involved in efforts to promote indigenous language preservation.

4. On March 21, 1963, the Oklahoma City Thunder basketball team played its first game in the National Basketball Association (NBA). The team, formerly known as the Seattle SuperSonics, moved to Oklahoma City in 2008 and has since become a beloved sports franchise in the state.

5. Finally, on March 21, 2006, the Oklahoma City Memorial Marathon was first run. The race, which honors the victims of the 1995 Oklahoma City bombing, has become one of the most popular marathons in the United States, attracting runners from all over the world to participate in the emotional and inspiring event.