1) On April 21, 1781, the Battle of Petersburg took place during the Revolutionary War. General William Phillips led British troops against Continental Army troops led by General Peter Muhlenberg. Despite being outnumbered, the Continental Army was able to repel the British attack.

2) On April 21, 1831, Nat Turner was convicted and sentenced to death for leading a slave rebellion in Southampton County. The rebellion, which took place in August 1831, resulted in the deaths of around 60 white people and over 100 black people.

3) On April 21, 1898, the Spanish-American War began with the United States declaring war on Spain. The war lasted less than four months and resulted in the United States acquiring territories such as Puerto Rico, Guam, and the Philippines.

4) On April 21, 1942, the Virginia Military Institute (VMI) suspended its academic program due to World War II. During this time, VMI cadets were trained in military skills and tactics to prepare them for service in the war.

5) On April 21, 2007, the Virginia Tech shooting took place, where a gunman killed 32 people and injured 17 others on the campus of Virginia Tech in Blacksburg, Virginia. It remains the deadliest school shooting in United States history.