On March 3, 1849, in his last hours in office, President James K. Polk signed the bill creating Minnesota Territory, a vast region stretching from the St. Croix River and Lake Superior to the Missouri River and north to the Canadian border, with more than 166,000 square miles divided into nine counties, including Wabashaw. As pressure mounted to organize the upper Mississippi country, settlers poured in after Iowa and Wisconsin entered the Union, while lands long used by Dakota, Ojibwe, and other Indian people, and shared since the later 1600s by Native people, Europeans, and Americans through trade and family ties, were increasingly claimed and renamed. During the territorial years, Dakota and Ojibwe people ceded nearly all of their lands in Minnesota to the U.S. government through treaties in exchange for money, promises, and reservations, even as settlements such as St. Paul, Stillwater, and St. Anthony grew rapidly, farms and towns spread, and the settler population rose from less than 5,000 in 1849 to more than 100,000 before statehood in 1858. When territorial legislators drew county lines in 1849, Wabashaw County spanned the entire width of the territory, though the town of Wabasha, founded in 1843 and later the county seat, was older; it stood upriver from the village of Dakota chief Wapashaw, the last of three hereditary chiefs of that name, whose band occupied the country below Lake Pepin, and whose name was traditionally said to mean red leaf or cap. Although a few white settlers had settled along the Mississippi River in the 1830s, southern Minnesota Territory did not officially open to settlers until several years after the 1851 Dakota treaties, but immigrants still rushed in by steamboat and covered wagon to claim land, and from 1850 to 1860 the population of Wabashaw County grew from 243 white and mixed-blood residents to nearly 5,000 in a much smaller area. Debate over statehood in 1857 also determined the state's final north-south shape, and after repeated boundary changes carved many new counties from Wabasha County's original expanse, the remaining county lay along the Mississippi as a place of small farms and river towns.