1. The city of Milwaukee was incorporated on March 9, 1846. The city was officially established as a separate entity from the surrounding towns and settlements in the area, and quickly became a major center of commerce and industry.

2. On March 9, 1891, the Wisconsin state legislature passed the first-ever workers' compensation law in the United States. The law provided for compensation to be paid to workers who were injured on the job, and was a major milestone in the rise of labor rights and protections in the country.

3. Wisconsin native Russ Feingold was born on March 9, 1953. Feingold served as a United States Senator from Wisconsin from 1993 to 2011, and is known for his advocacy of campaign finance reform and civil liberties.

4. On March 9, 1934, the deadliest tornado in Wisconsin history struck the southeastern part of the state. The tornado killed 17 people and caused millions of dollars in damage, and remains one of the most devastating natural disasters in Wisconsin history.

5. Wisconsin voters held their presidential primary elections on March 9, 2010. The primary was closely watched as a test of the strength of the Tea Party movement, with Wisconsin businessman Ron Johnson ultimately winning the Republican nomination for US Senate.