There are many ways to finish this statement. One way of completing it would be "... had dwindled significantly." With the conclusion of The Wounded Knee Massacre, Native American populations had become significantly less. The combination of White settlement into Native American land, destruction of food sources in both land and game, and the attrition of Native Americans through conflict had resulted in a decrease of Native American population. Another way to complete the thought would be "... experienced a great humiliation." From the time of the first settlers and the openness and collaboration the Native Americans offered to the end of the Indian Wars, one sees a very distinct and disparaging arc of development in Native American culture. The population had experienced much in way of social humiliation and political isolation as a result of their interaction with White Society. In the final analysis, one can trace the fall and complete dissolution of the Native American society and way of life through the Indian Wars. A final way to complete the sentence would be "... felt the full force of the pain which lies at the heart of the American Dream." The vision of America as one where individuals can carve out their own destiny with a sense of autonomy and freedom seems to come with some level of cost to it. Native Americans were the ones to bear the brunt of said cost. As White settlers pursued their dreams in the New World and continued the process with Western Expansion, each step towards the act of creation in that dream led to the inevitable destruction of the Native American shared way of life. This translated into a great deal of success and satisfaction only to be met by a sense of despair and agonizing forlornness. Such dichotomy speaks of the essence of what America is, what is hopes to be, and what can only strive not to be in its future.
...a variety of cultures which had been completely wrecked." There were probably no more than three million Native Americans in what became Canada and the US when Jamestown was founded in 1607, the vast majority living in the Southeast and Northeast. It took white Americans over two centuries to conquer the nations east of the Mississippi, but little more to complete the Indian Wars. The truth is that once Lewis and Clark proved President Jefferson had caused the US to purchase what was the most valuable real estate in the world there was no way the white settlers, government and business interests were going to let the approximately three thousand Indians who lived there keep it. The discovery of gold in the Black Hills and such situations made the process a little faster, but the main impetus was simply the land itself. The central plains of North America is the richest farmland on the planet, and the lure was irresistible.
The process, from the Powhatan War of 1622 to the Massacre at Wounded Knee took about 270 years. Most Native cultures were completely destroyed, only a shadow of some remaining in the West. Red Cloud was the only Indian leader to actually win a war with the US, although the reservation he accepted and many of the freedoms his people were guaranteed were eroded over time. The worst defeat by the Natives was visited on two US Army regiments in 1791 at the Battle of the Wabash, where some 623 soldiers were killed under the command of Gen. Arthur St. Clair by the Miami nation under Little Turtle.