1. On April 11, 1816, the Illinois Territory was established by an act of Congress. This new territory at that time included what is now Illinois, parts of Wisconsin and Michigan, and a portion of Minnesota.

2. On April 11, 1865, Union General James Wilson and his cavalry entered into Tuscaloosa, Alabama, marking the end of the Civil War in Alabama. This victory by the Union forces helped lead to the surrender of Confederate General Robert E. Lee just a few days later.

3. In 1893, on April 11, the World's Columbian Exposition opened in Chicago. This huge event was organized to celebrate the 400th anniversary of Columbus' discovery of America, and attracted millions of visitors from all over the world. This event showcased new technologies that are now commonplace today, such as the Ferris Wheel.

4. In 1974, on April 11, Hank Aaron of the Atlanta Braves hit his 715th home run, breaking Babe Ruth's record. This historic event took place at Fulton County Stadium in Atlanta, Georgia, and was a major moment for both baseball and African-American athletes.

5. On April 11, 2004, Mayor Richard Daley of Chicago declared "Pollution Awareness Day" in the wake of a report that detailed Chicago's high levels of pollution. This day was meant to raise awareness of the harmful effects of pollution on the environment and public health, and to encourage individuals and companies to take action to reduce their emissions.