1. Abraham Lincoln's First Debate: On September 27, 1858, Abraham Lincoln and Stephen A. Douglas held the first in a series of debates for the Illinois U.S. Senate seat. This debate, held in Ottawa, Illinois, drew a crowd of around 10,000 people and set the tone for the rest of the campaign.

2. Chicago Fire: On September 27, 1871, the Great Chicago Fire began. Over the course of three days, the fire destroyed over three square miles of the city, leaving over 100,000 people homeless and causing an estimated $200 million in damages.

3. The First Telephone Exchange: On September 27, 1892, the first telephone exchange in Chicago was opened. This exchange allowed people to make phone calls to other parts of the city for the first time, revolutionizing communication in the Windy City.

4. Illinois Poet Laureate: On September 27, 1936, Carl Sandburg was named Illinois Poet Laureate. Sandburg, who had written extensively about Chicago, the Midwest, and Abraham Lincoln, would hold the position until his death in 1967.

5. First Woman Elected to Congress: On September 27, 1946, Margaret Chase Smith was elected to the U.S. House of Representatives from Maine. Smith, a Republican, was the first woman to be elected to both houses of Congress and would go on to serve in the Senate as well.