Nine tornadoes strike southern Minnesota, particularly the towns of Waseca, Owatonna, and Albert Lea, killing thirteen people.

In his first home run for the Minnesota Twins baseball team, Harmon Killebrew hits the ball 467 feet.

Charles Joy makes the first automobile ascent of St. Paul's Selby Hill, at a speed of eight to ten miles per hour.

Troops from the U.S. Sixth Infantry begin constructing Fort Ridgely, having arrived from Fort Snelling on the steamer West Newton the previous evening. The fort is built near the Dakota reservation in the Minnesota River valley and would be a focal point during the U.S.-Dakota War of 1862. Secretary of War Jefferson Davis names the fort for three Ridgelys who were killed in the Mexican War.

The Louisiana Purchase is signed, transferring to the United States territory that includes present-day Minnesota west of the Mississippi River.

Entertainer Daniel D. Emmett obtains a business license for his "Ethiopean Minstrels," a blackface minstrelsy group. Emmett visited the state often in the 1850s while his brother Lafayette served as chief justice of the Minnesota Supreme Court, and it is believed that while here he wrote an early version of "Dixie," which was performed at Russell C. Munger's music store in St. Paul.

Congress passes a law that extends fur-trading licenses to US citizens only. Soon after, John J. Astor's American Fur Company pushes out its British rivals, the Hudson's Bay and North West Companies.

A fire destroys the St. Paul Public Library at Seventh and Wabasha Streets. The library resides in the old House of Hope Presbyterian Church building at Fifth and Exchange Streets and later moves into its present building across from Rice Park.

Vietnam War protestors stage a demonstration at Honeywell, Inc., which at the time manufactured fragmentation bombs.

In a Prohibition scandal, two agents are arrested for stealing $100,000 in confiscated liquor that had been stored in a Minneapolis warehouse. Eventually, four agents are suspended and warrants are issued for seven others.