1. On March 16, 1820, Maine became the 23rd state in the United States. Its admission to the Union came as a result of the Missouri Compromise, which allowed for Maine's entry as a free state while Missouri entered as a slave state.

2. In 1905, the University of Maine was established on March 16. Today it is one of the state's largest public universities and serves as an important center of learning and research.

3. On March 16, 1862, the First Maine Cavalry was engaged in a skirmish with Confederate forces in Virginia during the American Civil War. The regiment was one of several from Maine that served in the war, playing an important role in several key battles.

4. The Maine State House, the seat of the state government, was completed on March 16, 1832. Designed by architect Charles Bulfinch, the building is known for its distinctive dome and classic Greek Revival architecture.

5. On March 16, 1846, Maine native Hannibal Hamlin was selected to be the running mate of Democratic presidential candidate James K. Polk. Hamlin went on to serve as Vice President of the United States from 1861 to 1865 during the presidency of Abraham Lincoln.