 Until the 1850s the Native American population vastly outnumbered the population of European ancestry in the area . Nevertheless , the division between " Indian " and " white " during this era was always somewhat vague . In general persons of mixed descent were considered " white " if they dressed in European clothing and adopted European customs . " Indians " were those who lived in traditional native lifestyles . Even as the U.S. began to establish its authority over the region and some settlers from the U.S. began to arrive the Native American population continued to hold significant political and social influence as a result of the fur trade . As experienced hunters they were important to one of North America 's major business enterprises . The decline of this trade during the later part of the era marked the decline of Native American influence . 
