Why Did the American Frontier Close?

Over a period of about three fifty years, from when the white explorers first crossed over to America in search of a fresh start away from taxes, crime and persecution, the Native Indians Frontier had gradually been drawing to an end. The explorers constantly broke agreements with the Natives about their territories and many skirmishes left countless dead, most of which were Indians. Eventually in 1890 the Director of US census bureau finally announced that the frontier was closed.
At first the Indians and explorers met peacefully and exchanged gifts and traded with each other. The white people began to spread across America on covered wagons, most trying to find a new life, wealth or escape religious persecution, war, crime and tax. …