1. The first Boy Scout troop in Oklahoma was organized on April 21, 1910, just two years after the founding of the Boy Scouts of America. Troop 1 was established in Oklahoma City and was followed by many other troops throughout the state.

2. On April 21, 1935, the infamous "Dust Bowl" storm swept through Oklahoma, creating giant clouds of dust that blocked out the sun and caused widespread damage to crops and farmland. This event had a major impact on the state's economy and led many Oklahomans to seek a better life elsewhere.

3. The Oklahoma City Thunder basketball team made their first playoff appearance on April 21, 2010, winning a close game against the Los Angeles Lakers. The Thunder went on to make the playoffs for several consecutive seasons and developed a large and devoted fan base across the state.

4. The Oklahoma Land Run of 1889 officially began on April 22, but many settlers actually began their journeys a day earlier, on April 21. This event marked the opening of the Unassigned Lands in central Oklahoma to non-Native American settlement and led to the rapid growth and development of several major cities, including Oklahoma City and Tulsa.

5. On April 21, 1975, Oklahoma governor David Hall signed a bill into law that made the state the first in the nation to abolish the death penalty. The law was eventually overturned in 1976, but the state did not resume executions until 1990. Today, Oklahoma is among the states with the highest per-capita rates of executions in the US.