The members of Captain Stephen Kearny's expedition to find a road from Council Bluffs, Iowa, to Fort St. Anthony (later called Fort Snelling) arrive at Lake Pepin, having lost their way. Kearny then marches his men north to the fort.

Lewis Cass, governor of Michigan (which at the time included present-day Minnesota), reaches what he erroneously believes to be the source of the Mississippi River: a lake called Gaa-miskwaawaakokaag (where there are many red cedars) by the Ojibwe. Afterward, settler-colonists began to call it Cass Lake.

Minneapolis holds its first Aquatennial, a festival celebrating Minnesota's summers.

Two people are killed and sixty-seven are injured in a clash between strikers and police during a truckers' strike in Minneapolis. After federal mediation fails, Governor Floyd B. Olson declares the city under martial law, and the National Guard takes control of the streets.

The Western Federation of Miners calls a strike on the Mesabi Iron Range. Two hundred union men had been laid off from Mountain Iron Mine, owned by the Oliver Iron Mining Company, a subsidiary of US Steel. Although layoffs on the range were common, at issue was recognition of the union, which was threatened by the discharge of only union workers. Within two months a large number of imported scabs undermine the union's efforts and the strike is broken.

Polk County is established and named for James K. Polk, who was president when Congress authorized creation of Minnesota Territory.

Bagone-giizhig (Hole-in-the-Day the Younger), Eshkibagikoonzh (Flat Mouth), Lawrence Taliaferro, Henry H.

The Minnesota Twins retire number 29 in honor of Hall-of-Famer Rod Carew.

African American citizens in North Minneapolis begin a sometimes violent demonstration against police brutality along Plymouth Avenue that starts at about 11:30 P.M. and lasts for two nights. After a pause, a second wave of demonstrating begins that night after Samuel Simmons, an African American, is shot during an argument in a Northside bar.

Franklin Steele formally takes possession of the Fort Snelling military reservation, which he had bought from the government for $90,000. Although Steele envisioned a city on the grounds of the fort, this idea failed and Steele was unable to keep up the payments. During the Civil War the government reasserted its claim to the fort, which would remain in government hands until after World War II.