The U.S. created the Minnesota Territory in 1849. At the time, it contained much of the eastern part of what is now both North Dakota and South Dakota. Emigration from Europe, particularly from Germany and Sweden, swelled. The timber industry was a particularly strong draw for many settlers.

One American who helped popularize Minnesota was Henry Wadsworth Longfellow, whose The Song of Hiawatha, which described many parts of Minnesota, was published in 1855.

Minnesota residents submitted a proposal for admittance to the United States in late 1856; Congress approved the proposal two months later, but statehood was delayed for a time by political differences in Minnesota over the contents of the state constitution and by political differences in Congress over the possibility of slavery in another state.

On May 11, 1858, Minnesota (the eastern part of the Minnesota Territory) became the 32nd state in the Union.