High Quality Content by WIKIPEDIA articles! The territorial era of Minnesota covers the history of the land that is now the modern U.S. state of Minnesota from the Louisiana Purchase in 1803, to its achieving statehood in 1858. The Minnesota Territory itself was formed only in 1849 but the area had a rich history well before this. Though there was a long history of European presence in the area before 19th century, it was during the 19th century that the United States began to establish a firm presence in what would become Minnesota.