1. Vermont officially became the 14th state in the United States on December 18, 1791. The state had previously functioned as an independent republic after declaring its independence from Great Britain in 1777.

2. One of Vermont's most iconic landmarks, the Bennington Battle Monument, was completed on December 18, 1890. The monument stands 306 feet tall and commemorates the Battle of Bennington, which was a pivotal American victory during the Revolutionary War.

3. The Vermont state flag, which features the state's coat of arms against a blue background, was first flown on December 18, 1923. The coat of arms includes numerous symbols representing Vermont's history and culture, such as a cow for the state's famous dairy industry and a pine tree for its lush forests.

4. In 1985, Vermont became the first state in the nation to recognize civil unions for same-sex couples. This landmark decision was made by the Vermont Supreme Court on December 18 of that year, paving the way for further advancements in LGBTQ rights nationwide.

5. December 18 is also National Twin Day, a holiday celebrating multiples born on the same day. Vermont has its fair share of famous twins, including Mary-Kate and Ashley Olsen, who were born in Sherman Oaks, California but spent much of their childhood in Burlington, Vermont.