1. In 1836, the Battle of San Jacinto took place on April 18th, resulting in the defeat of General Santa Anna and ultimately securing Texas's independence from Mexico.

2. In 1876, Texas A&M University held its first graduation ceremony on April 18th, with six students receiving their diplomas.

3. In 1936, the Texas Centennial Exposition opened in Dallas on April 18th, celebrating 100 years of Texas independence and showcasing the state's progress and achievements.

4. On April 18, 1942, sixteen B-25 bombers took off from the USS Hornet and conducted a surprise bombing raid on Tokyo, considered one of the most daring and successful military operations in history and led by Texan Lieutenant Colonel Jimmy Doolittle.

5. On April 18, 1989, the tragedy of the "Rio Grande Valley Flash Flood" took place, resulting in 20 deaths and extensive damage across the region due to heavy rainfall and flooding.