1. In 1861, the Illinois state legislature passed a resolution recognizing the existence of a state of war between the United States and the Confederacy, and pledged the full support of the state to the federal government in its effort to preserve the Union.

2. On May 13, 1874, the world-renowned author and humorist Mark Twain delivered a lecture in Springfield, Illinois, entitled "The Adventures of Tom Sawyer." The lecture was well-received by the audience, and helped to further establish Twain's reputation as a popular and influential writer.

3. In 1907, the city of Chicago inaugurated its first electric streetcar line, marking a major milestone in the history of urban transportation in the city. The streetcar network would eventually grow to become one of the largest and most extensive in the world, and would play a major role in shaping the development of Chicago in the 20th century.

4. In 1917, the state of Illinois passed a law allowing women to serve on juries for the first time. The law was seen as a major step forward for women's rights and was widely praised by advocates for gender equality.

5. On May 13, 1985, heavy rainfall and severe thunderstorms caused severe flooding in northern Illinois, with some areas receiving more than 10 inches of rain in a 24-hour period. The flooding caused widespread damage to homes and businesses, and resulted in several fatalities. The disaster served as a reminder of the need for robust flood control measures in the region.