1. Connecticut became the fifth state in the US on December 31, 1787, when it ratified the Constitution. The Constitution was signed two months prior, but each state had to individually ratify it to become a part of the federal government.

2. The state's first female governor, Ella Grasso, made history on December 31, 1974, when she was sworn in for her second term. Grasso served as Connecticut's governor from 1975 to 1980 and was well-known for her tireless work to improve the state's economy and education system.

3. On December 31, 1983, the Connecticut Huskies football team claimed their first bowl victory in school history. The Huskies defeated the Western Carolina Catamounts 20-10 in the first round of the NCAA Division I-AA playoffs.

4. The iconic and historic Mystic Seaport Museum in Mystic, Connecticut, opened its doors to visitors on December 31, 1929. The museum has since become one of the state's most popular tourist attractions, offering visitors a glimpse into the history and culture of Connecticut's waterfront communities.

5. Finally, on December 31, 1991, the Connecticut River flood of 1991 reached its peak, causing widespread damage to homes and businesses throughout the state. The flood was caused by heavy rains and snowmelt, and it affected the entire Connecticut River basin from Massachusetts to Long Island Sound. Despite the damage, communities across the state came together to rebuild and recover in the months and years that followed.