1. In 1823, the United States government opened land for settlement in what is now Waukesha County. This led to the establishment of towns like Brookfield and Pewaukee.

2. December 20, 1832 saw the first boatload of lead ore from the lead mines of southwest Wisconsin shipped down the Mississippi River to New Orleans. This helped to establish the mining industry in the state.

3. In 1864, the Milwaukee and St. Paul Railroad opened a line between Milwaukee and Prairie du Chien. This made it easier for goods to be transported throughout the state and helped to spur economic growth.

4. On December 20, 1907, the city of Manitowoc was hit by a severe snowstorm. The storm dumped nearly two feet of snow on the town and caused widespread damage.

5. In 2011, the Wisconsin Badgers football team played in the inaugural Big Ten Championship game. The game was held on December 20 at Lucas Oil Stadium in Indianapolis and saw the Badgers defeat the Michigan State Spartans 42-39.