Only a handful of tornadoes each year cause loss of life and/or significant property damage- and such storms are certainly a significant part of American history. But a particularly costly storm in 1948 not only made history, it changed our very understanding of tornadoes themselves, resulting in the first tornado forecast.
There is legitimate controversy over which ship was America’s first true battleship. But the Navy answers that question relatively clearly- USS Indiana was, from the outset, called "Battleship Number One."