1. On February 21, 1836, the Battle of San Jacinto began in present-day Harris County, Texas. This final battle of the Texas Revolution lasted only 18 minutes, resulting in a decisive victory for the Texian army led by General Sam Houston and securing Texas' independence from Mexico.

2. In 1856, the Texas legislature granted a charter to Baylor University, a private Christian university located in Waco. Today, Baylor is the oldest continuously operating university in Texas and is known for its nationally ranked academic programs and top-tier athletics.

3. On February 21, 1839, Mirabeau B. Lamar was inaugurated as the second president of the Republic of Texas. During his term in office, Lamar focused on expanding Texas' borders and promoting its economic development. He is also credited with establishing several state institutions, including the Texas State Library and the University of Texas at Austin.

4. The first recorded public performance of the iconic song "Deep in the Heart of Texas" took place on February 21, 1942, at the Majestic Theater in San Antonio. The song, which has since become a cultural symbol of Texas, was written by June Hershey and Don Swander and first recorded by Perry Como in 1942.

5. February 21, 1960, marked the beginning of the Woolworth's lunch counter sit-ins in several Texas cities, including Houston, Dallas, and Fort Worth. The nonviolent protest was organized by African American college students and aimed to challenge the practice of segregation in public places. The sit-ins attracted national attention and ultimately helped to catalyze the civil rights movement in Texas and across the country.