Minnesota passes the nation's first direct primary election law, which applies to candidates running for city and county offices in counties with a population of 200,000 or more (at the time, only Hennepin County qualifies). Wisconsin would be the first state to make statewide direct primaries the law in 1903; while Minnesota had drafted similar legislation applicable to city and county offices in 1901, the state's officers and U.S. senators would not be elected by direct primary until 1912.

Itasca State Park, Minnesota's first, is established. Its 32,000 acres preserve more than 300 lakes as well as the headwaters of the Mississippi River.

George Morrison, an abstract painter and sculptor, dies. Born in Chippewa City, near the Grand Portage Indian Reservation of Ojibwe, in 1919, Morrison had pursued a career in art that took him to New York, Paris, Ohio, and Rhode Island.

The Red River crests at 39.5 feet, 22.5 feet above flood stage at Fargo, breaking a 100-year-old record. Continuing into Grand Forks, North Dakota, and East Grand Forks, Minnesota, on April 21 the flood pushes water levels to 54.2 feet, 26.2 feet above flood stage. The worst flooding in the area in over a century, it causes more than one billion dollars of damages and displaces 47,000 of the 50,000 residents of Grand Forks.

The Mississippi River crests in St. Paul at 25.8 feet, nearly ten feet above flood stage. Three days earlier, President Lyndon B. Johnson had visited St. Paul to survey damages from record flooding along the Minnesota and Mississippi Rivers. In the flood's wake, losses are estimated at $88 million and numerous counties across the state are declared federal disaster areas.

"Hail! Minnesota" becomes the state song. Written by two University of Minnesota students in 1904 and 1905, it is also the university's official song.

Duluth's public library opens.

On a national day of mourning for President Abraham Lincoln, St. Paul businesses close and city officials wear black armbands. The courthouse is draped in black for thirty days.

The first recorded mention of farming by white Minnesotans is made in a letter written by George H. Monk, who notes crops of potatoes, oats, cabbages, beets, beans, pumpkins, and Indian corn being cultivated at the North West Company's fur trading posts on Sandy and Leech Lakes.

The Minnesota State Lottery begins selling instant tickets. Within four months, sales reach $100 million.