1. Vermont becomes the 14th U.S. state – On April 20, 1791, Vermont officially became the 14th state to join the United States of America. The state had been an independent republic for 14 years prior to this, and it is the only state to have existed as an independent nation before joining the Union.

2. Vermont's first state governor takes office – On April 20, 1791, Thomas Chittenden took office as Vermont's first governor after the state's admission to the Union. Chittenden went on to serve a total of 17 years as governor, making him the longest-serving governor in the state's history.

3. Vermont ratifies the U.S. Constitution – On April 20, 1790, Vermont ratified the U.S. Constitution, becoming the first state to do so after the original 13 colonies. This move helped to solidify Vermont's position as a state in the Union.

4. Vermont's first natural gas pipeline is completed – On April 20, 1951, Vermont's first natural gas pipeline was completed, bringing this important energy source to the state for the first time. This allowed for the development of new industries and helped to fuel the state's growth in the post-war years.

5. Vermont celebrates its first Earth Day – On April 20, 1970, Vermont celebrated its first Earth Day, marking the beginning of a new environmental movement in the state. The event was held in many cities around the world, and it helped to draw attention to the need for greater environmental protection and conservation efforts.