1. The Illinois Statehood Day is celebrated on March 3 annually, which marks the day Illinois officially became the 21st state of the United States in 1818.
2. On March 3, 1837, the famous politician Stephen A. Douglas delivered his first speech in the Illinois House of Representatives, which eventually propelled him to become one of the most influential senators in US history.
3. March 3, 1931, marked the opening of the Sears Tower in Chicago, which was the world's tallest building until 1998 and remains the tallest building in the United States.
4. The Illinois State Capitol building in Springfield was completed on March 3, 1888. It is an iconic example of neoclassical architecture and serves as the seat of the Illinois General Assembly and the offices of the governor and lieutenant governor.
5. Governor Pat Quinn of Illinois signed the Religious Freedom and Marriage Fairness Act into law on March 3, 2013, which made Illinois the 16th state in the US to legalize same-sex marriage.