1. On March 21, 1918, the State of Connecticut declared war on Germany during World War I. This was in response to the German government's unrestricted submarine warfare campaign against American merchant ships.

2. In 1963, on March 21, the University of Connecticut's men's basketball team won their first NCAA tournament game in program history. They defeated Temple University 53-49 in the first round, beginning a tradition of basketball excellence at UConn.

3. On March 21, 1956, the Connecticut House of Representatives approved a bill that would ban the sale and possession of marijuana. This was one of the first state-level efforts to criminalize marijuana in the United States.

4. In 1789, on March 21, the Connecticut General Assembly ratified the United States Constitution, becoming the fifth state to do so. Connecticut played a significant role in the founding of the country, sending delegates to the Continental Congress and playing an important role in the drafting of the Constitution.

5. March 21, 1983, was a significant day in Connecticut transportation history. This was the day that the first Hartford-New Haven commuter train began service on the newly restored rail line. This rail line had been abandoned in the 1960s, but after years of planning and investment, it was reopened to the public in the 1980s as part of a larger effort to improve public transportation in Connecticut.