Henry Longstreet Taylor was a key figure in the development of tuberculosis treatment in Minnesota. The sanatoriums he helped establish in the early 1900s were an essential part of a statewide anti-tuberculosis campaign to control and study the disease.

During the Civil War era, Fort Snelling served as an induction and training center for nearly twenty-five thousand soldiers. Many of them fought in the Civil War. Around fourteen hundred of the troops raised at the fort served in the US–Dakota War of 1862. After that war, a concentration camp for Dakota non-combatants was established near the fort. Following the Civil War, the fort supported US military expeditions against Indigenous people and the garrisoning of western posts.

Bonanza farms—large, commercial farming enterprises that grew thousands of acres of wheat—flourished in northwestern Minnesota and the Dakotas from the 1870s to 1920. Geology, the Homestead Act of 1862, railroads, modern machinery, and revolutionary new flour-milling methods all contributed to the bonanza farm boom.

With the fall of Fort Sumter in 1861, Minnesota became the first state to offer troops to fight the Confederacy. Josias Redgate King is credited with being the first man to volunteer for the Union in the Civil War.

The Interstate 35W bridge over the Mississippi River in Minneapolis collapses during the evening rush hour. Thirteen people are killed and 145 are injured.

Demolition of the Hubert H. Humphrey Metrodome begins.

Some state government agencies and departments are shut down because of an impasse between Governor Tim Pawlenty (R) and the DFL-controlled senate. Almost 8,900 state employees are furloughed for nine days until a compromise is reached.

Light rail service between the Minneapolis and St. Paul downtowns begins. Called the Green Line, the eleven-mile line passes through the University of Minnesota campus and along University Avenue.