1) In 1836, the Battle of San Jacinto, also known as the "birthplace of Texas independence," took place on April 12. This battle resulted in the defeat of Mexican forces and led to the formation of the Republic of Texas.

2) On April 12, 1861, the Civil War began with the Confederate attack on Fort Sumter in South Carolina. Texas was one of the Southern states that seceded from the Union and joined the Confederacy during the war.

3) In 1945, President Franklin D. Roosevelt passed away on April 12, which led to the immediate inauguration of Vice President Harry Truman as the 33rd President of the United States. Texas was a crucial state in Truman's eventual victory in the 1948 presidential election.

4) On April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first person to orbit the Earth. This historic achievement helped kick-start the Space Race between the Soviet Union and the United States, which had a major impact on the development of the space industry in Texas.

5) Finally, on April 12, 2003, President George W. Bush declared an end to major combat operations in Iraq, signaling the beginning of a long and difficult period of post-war reconstruction and diplomacy. Texas played an important role in both the military action and humanitarian efforts during the Iraq War.