1. The first constitutional convention of Vermont was held on May 18, 1777 in Windsor, Vermont. During the convention, the Vermont Constitution was written, making Vermont the first state to abolish slavery.

2. On May 18, 1800, the Vermont legislature authorized the construction of the Middlesex Turnpike, which connected Montpelier and Middlesex. It was later extended to Waterbury in 1805.

3. The Vermont Central Railroad was organized on May 18, 1843. It was later merged with several other railroads to become the Central Vermont Railway.

4. On May 18, 1875, the Vermont legislature passed a law prohibiting the sale and manufacture of liquor in the state. This law stayed in effect until it was repealed in 1902.

5. On May 18, 1929, the Vermont legislature passed an act establishing the Vermont Fish and Game Department. The department's mission is to protect and manage Vermont's fish, wildlife, and their habitats.