1. The sinking of the SS Milwaukee: On April 15, 1929, the SS Milwaukee, a passenger steamship on Lake Michigan, sank during a violent storm. Only three of the 52 people on board survived the tragedy.

2. First game at Miller Park: April 15, 2001, marked the opening of Miller Park, the home of the Milwaukee Brewers baseball team. The first game was played between the Brewers and the Cincinnati Reds, and the Brewers won 5-4.

3. Green Bay Tornado: On April 15, 1958, a violent tornado struck the city of Green Bay, causing 21 fatalities and over $50 million in damages. It was one of the worst tornadoes in Wisconsin history.

4. Ice Age Scenic Trail: On April 15, 1980, the Ice Age National Scenic Trail was designated by Congress. This 1,200-mile trail follows the path of the last glaciers that covered Wisconsin, and offers visitors the opportunity to explore the state's unique glacial landscape.

5. Women's Right to Vote: On April 15, 1919, Wisconsin became the first state in the nation to ratify the 19th Amendment, which granted women the right to vote. This was a significant moment in the history of women's suffrage in the United States.