While this theory received support in popular imagination and academia for years, recently, scholars such as historians Tai S. Edwards and Paul Kelton argue that Native Americans "'died because U.S. colonization, removal policies, reservation confinement, and assimilation programs severely and continuously undermined physical and spiritual health.

'"[11] According to these scholars, certain Native populations did not necessarily plummet after initial contact with Europeans, but only after violent interactions with colonizers, and at times such violence and colonial removal exacerbated disease's effects.

Additionally, conflicts, massacres, forced removal, enslavement, imprisonment, and warfare with European settlers contributed to the reduction in populations and the disruption of traditional societies.

Native American peoples still face challenges stemming from colonialism, including settler occupation of their traditional homelands, police brutality, hate crimes, vulnerability to climate change, and mental health issues.

[19] The Indigenous peoples of the Pacific Northwest Coast were of many nations and tribal affiliations, each with distinctive cultural and political identities, but they shared certain beliefs, traditions, and practices, such as the centrality of salmon as a resource and spiritual symbol.

The Iroquois League of Nations or "People of the Long House" was a politically advanced, democratic society, which is thought by some historians to have influenced the United States Constitution,[24][25] with the Senate passing a resolution to this effect in 1988.

[26] Other historians have contested this interpretation and believe the impact was minimal, or did not exist, pointing to numerous differences between the two systems and the ample precedents for the constitution in European political thought.

[30] The Oceti Sakowin belief of Mni Wiconi (water is life), for instance, describes a relationship in which the Missouri River nourishes their community, and they have a responsibility to protect it.

Four days later, the militias from the English colonies of Plymouth, Connecticut, and Massachusetts Bay were led to the main Narragansett town in South Kingstown, Rhode Island.

"[42][44] During Pontiac's War, Colonel Henry Bouquet conspired with his superior, Sir Jeffrey Amherst, to infect hostile Native Americans through biological warfare with smallpox blankets.

To resolve this issue, George Washington ordered the Continental Army, under the command of John Sullivan and James Clinton, to conduct a series of scorched earth campaigns against the four British-allied nations of the Iroquois Confederacy.

Smith refers to monuments, markers, and places bearing the name of the expedition as a celebration of colonialism and domination, and she argues that they affect how local residents relate to their past.

Smith shows that Haudenosaunee populations are harmed by this commemorative complex that pinpoints the sites of destruction on their ancestral lands and seeks to replace Native memory.

In a policy formulated largely by Henry Knox, Secretary of War in the Washington administration, the U.S. government sought to expand into the west through the purchase of Native American land in treaties.

Three landmark Supreme Court cases, the Marshall Trilogy, invoked the Doctrine of Discovery to declare that Native Americans were domestic dependent Nations and only had limited sovereignty on their own land.

The national policy was for the Indians to join American society and become "civilized", which meant no more wars with neighboring tribes or raids on white settlers or travelers, and a shift from hunting to farming and ranching.

[70] Historians such as David Stannard[71] and Barbara Mann[72] have noted that the army deliberately routed the march of the Cherokee to pass through areas of a known cholera epidemic, such as Vicksburg.

[105] Following the Gold Rush, there were a number of killings and state-subsidized massacres by settlers against Native Americans in the territory, causing several ethnic groups to be nearly wiped out.

[112] One contemporary wrote, "The miners are sometimes guilty of the most brutal acts with the Indians... such incidents have fallen under my notice that would make humanity weep and men disown their race".

For instance, at the turn of the 20th century, "one strategy of settler colonialism was to consolidate mobile family groups to sedentary villages with central nodes, such as a post office, government school and a mission.

"[97] Settler efforts to contain Natives not only removed them from these culturally significant environmental contexts, but also increased their vulnerability to climate change by impeding their ability to adapt to its impacts.

For nations that were not historically mobile, displacement and relocation presented challenges as well, as introduction to unfamiliar land "compromised the mental, physical, and community health of Indigenous peoples, thus escalating mortality rates.

[97] In her 2019 book As Long as Grass Grows, Colville Confederated Tribes scholar Dina Gilio-Whitaker supports Kyle Powys Whyte's argument that settler colonialism is a form of environmental injustice "that wrongfully interferes with and erases the socioecological contexts required for Indigenous populations to experience the world as a place infused with responsibilities to humans, nonhumans, and ecosystems.

[137] Lisa Brunner, executive director of Sacred Spirits First National Coalition states, "What's happened through US Federal law and policy is they created lands of impunity where this is like a playground for serial rapists, batterers, killers, whoever and our children aren't protected at all.

[145] In 1977, Marie Sanchez, chief tribal judge of the Northern Cheyenne Indian Reservation told the United Nations Convention on Indigenous Rights in Geneva, that Native American women suffered involuntary sterilization which she equated with modern genocide.

According to Tai S. Edwards and Paul Kelton, Southeastern Woodlands people "intentionally limited contact with colonial settlements during outbreaks, used ritualized quarantine to reduce the spread of disease, and relied on experienced healers to provide physical and spiritual treatment.

In 1974, Madonna Thunderhawk, a prominent member of AIM and WARN, founded the We Will Remember Survival School to teach Indigenous students about treaty rights and Native culture.

The Haudenosaunee have addressed the industrial pollution of the St. Lawrence River by utilizing organizations such as the Akwesasne Task Force on the Environment, the Mothers for Milk Project, and Traditional Mohawk Nation Council of Chiefs.

[94] In 2016, the Oceti Sakowin groups and allies protested the completion of the Dakota Access Pipeline that would threaten the Missouri River, the Standing Rock Indian Reservation's water supply.

[151] David Moshman, a professor at University of Nebraska–Lincoln, highlighted the lack of awareness of the American public, stating, "The nations of the Americas remain virtually oblivious to their emergence from a series of genocides that were deliberately aimed at, and succeeded in eliminating, hundreds of Indigenous cultures.