1. Statehood Day: May 28, 1907, marked an important day in Oklahoma history as it was the day the state was officially admitted to the Union as the 46th state.

2. Native American History: May 28 was also the day in 1830 when President Jackson signed the Indian Removal Act, which led to the forced removal of Native American tribes, like the Cherokee, from their ancestral lands in Oklahoma to Indian Territory.

3. Tornado Outbreak: On May 28, 1999, one of the deadliest tornado outbreaks in U.S. history occurred in Oklahoma, claiming 46 lives and injuring over 800 people. The tornadoes also caused extensive damage to homes and businesses in the affected areas.

4. OKC Bombing Anniversary: May 28 marks the anniversary of the deadliest act of domestic terrorism in U.S. history – the Oklahoma City bombing. On this day in 1995, a truck bomb exploded outside the Alfred P. Murrah Federal Building, killing 168 people and injuring hundreds more.

5. Military Heritage: May 28 is also significant in Oklahoma military history as it marks the anniversary of the Battle of Pusan Perimeter. This battle, which took place during the Korean War in 1950, was a significant turning point for U.S. forces as they were able to hold their ground against a much larger enemy force.