I’m not sure how this question defines “great civilization,” but it seems that, like most other people educated in the United States, the questioner is unaware of the highly stratified, centralized, and elaborate societies that did exist north of the Rio Grande prior to the arrival of Europeans. We are taught that Indian societies in North America had no governments, class structures, religions, intellectual traditions, or other elements of what Western European philosophy calls “civilization.” But to contrast that view, I'll offer a few examples. I think we can fairly say that all societies, regardless of how elaborate their social and political structures may be, are “civilized.” The largest city in North America prior to 1492 was called Cahokia, located on what is today the Missouri River across from St. Louis. As a city-state, the population of 15,000 people was comparable to London or Paris at that time. Cahokia was the center of an elaborate trade network that stretched across the entire continent from 950 to 1250 AD. City residents, along with laborers from far away, traveled to Cahokia over the course of several hundred years to build enormous earthen mounds. The largest one is 15 acres around and is the largest earthen structure in the Western Hemisphere. These mounds—not unlike European cathedrals in spiritual or architectural significance—served as symbols of power for elite religious and political leaders. These leaders often lived atop the mounds to be closer to the sun, their spiritual source of power. The influence these leaders possessed was enormous. Not only could they command the construction of mounds, but they held the reins of the city's economic and military fortunes as well. Because of the extent of Cahokia's trade networks, the consequences of their decisions were felt all over the continent.

Another immense center of trade and spiritual power was located in Chaco Canyon in what is now New Mexico. Inhabitants and visitors to the canyon built 12 structures between 900 and 1150 AD, which had 200 or more contiguous, multistoried rooms and numerous “kivas,” or round, windowless areas that today the Hopi and Pubelo Indians (descendants of the people who built Chaco) use for worship. Like Cahokia, the labor required to build such structures must have been enormous and well-coordinated, evincing a sophisticated political, economic, scientific, and social organization. Surrounding these 12 structures were between 200 and 350 villages in the canyon. An estimated 15,000 people inhabited the area. Among archaeologists, two theories are popular about why Chaco was built. The first centers on trade and exchange. Archaeologists have found items from Mexico and Central America in towns and villages up to 60 miles away from the central part of the canyon, along with a system of roads. This evidence leads them to speculate that the Chaco structures were the center of trade, where people bought and sold goods. The second theory involves the scientific and spiritual dimensions of the buildings. The structures are built in line with astronomical movements of the sun, moon, planets, and stars, leading some to believe that it was in fact a kind of three-dimensional calendar, a much more elaborate version of Stonehenge in England. Settlers in the canyon would have gone there to worship at certain times of the year to be reminded of the order of the universe and their place in it. Ultimately, both these scenarios could exist. Certainly by anyone’s standards, a society that so fully integrated spiritual, scientific, and material aspects of life would qualify as a “great civilization.” If, however, by comparing North and South America you mean to ask why did North America not develop the exact same kind of societies that Central and South America did, then one answer to that may be population density. Central Mexico alone had 25.2 million people in 1491, making it the most densely populated place on earth. The whole continent of North America, by contrast, had 12–20 million people. As we see throughout human history and all over the world, higher numbers of people tend to lead to more highly stratified societies.

Pershing undoubtedly had complex views on race and American citizenship, probably not so different from his political ally and fellow Republican, Theodore Roosevelt. Given his command of African American “Buffalo Soldiers” in the 1898 Spanish-American War and his participation in the Wounded Knee Massacre of Lakota Indians just eight years earlier, it would seem that he held very contradictory views. To Pershing, blacks may have seemed like worthy soldiers, while Indians deserved genocide. On the other hand, as a military officer, Pershing was carrying out orders and we cannot assume these actions reflected his personal beliefs. Roosevelt, however, was in a different position. Unlike Pershing, who followed orders, Roosevelt gave orders and thus set the tone for race relations both in the military and in society at large. For example, Roosevelt was determined to see the cultural extinction of American Indians (while holding them up as “noble savages” nonetheless), but he also hosted black educator Booker T. Washington at the White House, a very controversial move, especially to white Southern Democratic politicians.

As the first two decades of the 20th century passed, the nation saw increased immigration from both Europe and Asia, as well as increased activism by African Americans, American Indians, and others who demanded equal opportunities and the end of discriminatory laws and customs. World War I was a watershed in these movements, as both African Americans and American Indians enlisted in the army. Blacks served in segregated units, but Indians did not. Indians had a highly ambivalent attitude about their senses of belonging to the American nation; after all, they belonged to tribal nations as well, nations which had long histories of government-to-government relations with the United States. Yet by 1918, the federal government had done a good deal to not only destroy Indian lives but to destroy that government-to-government relationship as well. Many Indians were resentful of these policies, but chose to join the military anyway. Why? Veterans have offered many reasons, one of which is that they believed that when America was threatened, their homelands were threatened. Many veterans saw themselves as warriors not only for their own tribal communities but for the U.S. as well. Despite their service alongside whites, there is no doubt that Indians experienced a high degree of discrimination in the military, as sensitively shown by Joseph Boyden in the novel Three Day Road. Both Indians and blacks sacrificed for the United States and felt that the country ought to treat them more fairly. Woodrow Wilson, a Democrat who had to maintain political support from southern white supremacist Democrats, vacillated on this issue (especially in his refusal to support anti-lynching legislation in Congress) and questions of African American integration in the military were essentially abandoned until after World War II. Wilson, like so many other policy makers, seemed to effectively ignore Indian concerns. Indians’ service with whites in the military might be explained by the emerging notion of “whiteness.” Whiteness is an analytical category that historians have used to explain the shifts in race relations created by immigration and industrialization in the late 19th and early 20th centuries. We must remember that men like Roosevelt and Pershing talked about “race” in what today we would think of as ethnic or national terms—there was an English race, an Irish race, a German race, an Italian race, and so on. Today, we tend to think of these ethnicities as “white,” though that idea was hardly solidified in the early twentieth century. Instead, a long historical process created “whiteness” and a white population out of many different nationalities once perceived as incompatible and even threatening to Anglo-Saxon Americans.

Famously, Roosevelt believed in the “melting pot,” a phrase that we have come to associate with his belief in equality and the worth of all men, but which in actuality referred to his wish to see Americans with ancestry in Western Europe mix and marry one another. It was only those Americans who could jump into the melting pot—Asians, African Americans, American Indians, and others were explicitly excluded from Roosevelt’s vision of a strong American people. Yet, Indians were not segregated in military service, despite the fact that every American president had endorsed a policy that would essentially exterminate them. These policies had not wholly succeeded, but at the turn of the 20th century the American Indian population was at its lowest in human history. In this light, we can imagine that Indians were not perceived as a threat to whiteness in the same way that Southern Europeans, Eastern Europeans, Asians, and African Americans were. By the 1920s, immigrants from places seen as undesirable to Anglo-Saxon policy makers had increased so much that Congress passed the 1924 Immigration Act. This act installed quotas on immigrants from certain countries; in general, the number of immigrants from Southern and Eastern Europe and Asia could not exceed 2% of those populations currently living in the US, as of the 1890 census. In other words, if, say, 100,000 people from China lived in the United States in 1890, then the US would admit no more than 2,000 people in a given year. Pershing, who was close to President Calvin Coolidge and had even considered a run for the Republican Presidential nomination in 1920, was present for the signing of this bill, indicating his support for it and what it represented for policy-makers’ hopes about the future racial composition of the United States. Of course, we now know that this policy ultimately did not achieve its intended effect, however much “whiteness” is taken for granted today. Indeed, what this period shows is that the racial hierarchies we believe to have always been in place were in considerable flux even as recently as 100 years ago. Pershing, Roosevelt, Wilson, and Coolidge were at the forefront of maintaining white supremacy, but they could not ignore the consistent—and insistent—protest of non-white Americans, nor should we ignore the fact that within white and non-white communities, there are very distinct groups with different histories who possessed varied responses to their situations in the United States.

Lone Wolf v Hitchcock (187 U.S. 553, 1903) was part of a long string of treaties and legislative and judicial measures that displaced North America’s First Peoples from their ancestral lands, hemmed them into “reservations,” and eventually detribalized them. This Supreme Court decision originated on the Kiowa-Comanche reservation, which the Medicine Lodge Treaty (1867) had established in Indian Territory. The treaty guaranteed the Kiowa and Comanche “absolute and undisturbed use and occupation” of these reservation lands and stipulated that in order for any portion of the reservation lands to be ceded to the U.S., three-fourths of the adult males in the tribe had to give their approval. However, in 1900, without Native American consent, Congress passed an Allotment Act that divided the Kiowa-Comanche lands into 160-acre allotments to give to the Native American residents of the reservation. Those who accepted the allotments were also given American citizenship. The “surplus” lands left after the allotment were to be sold to whites, and the Kiowa and Comanche were to receive about one dollar per acre for these lands. In 1902, Kiowa headman Lone Wolf sued newly-appointed Secretary of the Interior Ethan Allen Hitchcock to stop the allotment of the Reservation. Lone Wolf argued that the allotment was a denial of due process and a violation of the consent requirement in the Medicine Lodge treaty. The federal government’s lawyers asserted that Congress had a right to alter the terms of the treaty through legislation, because it had paramount authority over Indian affairs. Justice A.C. Bradley of the Supreme Court of the District of Columbia rejected the Kiowa claim that the 1900 Act deprived tribes of due process. He stated that lack of consent was not relevant because Native American matters were under the exclusive control of Congress. The Court of Appeals upheld Bradley’s decision, and the United States Supreme Court agreed.

Justice Edward Douglas White’s opinion stated that Congress had the right to alter the terms of treaties with Native American tribes, because “authority over the tribal relations of the Indians has been exercised by Congress from the beginning, and the power has always been deemed a political one.” The judiciary could not interfere in Congress’s “plenary power.” This decision was based on the idea that Indians held dependent status to the United States government. Calling Native Americans “the wards of the nation,” White stated that “from their very weakness and helplessness, so largely due to the course of dealing of the Federal government with them and the treaties in which it has been promised, there arises the duty of protection, and with it the power.” This assertion of paternal dominion over Native Americans reversed the Supreme Court’s acknowledgment of a certain measure of Indian autonomy in previous cases, such as Worcester v Georgia 31 U.S. (6 Pet.) 515 (1832). Shortly after the decision, the U.S. opened Kiowa lands to white settlers, and over 50,000 settled on the “surplus” lands that Kiowa and Comanche had possessed under the Medicine Lodge Treaty. The “plenary power” doctrine first affirmed in Lone Wolf v Hitchcock is still valid Indian policy today.