1. In 1838, the first issue of the Illinois State Register was published in Springfield. The newspaper was initially a Whig publication and later became a Republican newspaper.

2. On April 6, 1852, the Chicago and Rock Island Railroad was incorporated. This railway was one of the first to connect Chicago to the Mississippi River and was vital in the growth of the city.

3. In 1917, the United States officially declared war on Germany, entering World War I. Illinois played a significant role in the war effort, with nearly 350,000 Illinoisans serving in the armed forces.

4. April 6, 1968 was a tragic day in Illinois history, as civil rights leader Dr. Martin Luther King Jr. was assassinated in Memphis, Tennessee. The news of King's death sparked riots and unrest across the country, including in Chicago.

5. On April 6, 2010, the Chicago Cubs played their first game at their new home, Wrigley Field. The iconic ballpark has been the home of the Cubs since 1916 and is a beloved landmark in Chicago.