Genocide of Native Americans participant United States of America
Indigenous peoples of the Americas (pre-1948)
It is estimated that during the initial Spanish conquest of the Americas, up to eight million indigenous people died, primarily through the spread of Afro-Eurasian diseases. Simultaneously, wars and atrocities waged by Europeans against Native Americans also resulted in millions of deaths. Mistreatment and killing of Native Americans continued for centuries, in every area of the Americas, including the areas that would become Canada, the United States, Mexico, Argentina, Brazil, Paraguay, Chile. In the United States, some scholars (examples listed below) state that the American Indian Wars and the doctrine of manifest destiny contributed to the genocide, with one major event cited being the Trail of Tears.Indian Removal and the Trail of Tears
Following the Indian Removal Act of 1830, the American government began forcibly relocating East Coast tribes across the Mississippi. The removal included many members of the Cherokee, Muscogee (Creek), Seminole, Chickasaw, and Choctaw nations, among others in the United States, from their homelands to the Indian Territory in the eastern sections of the present-day state of Oklahoma. About 2,500–6,000 died along the Trail of Tears.Chalk and Jonassohn assert that the deportation of the Cherokee tribe along the Trail of Tears would almost certainly be considered an act of genocide today. The Indian Removal Act of 1830 led to the exodus. About 17,000 Cherokees, along with approximately 2,000 Cherokee-owned black slaves, were removed from their homes. The number of people who died as a result of the Trail of Tears has been variously estimated. American doctor and missionary Elizur Butler, who made the journey with one party, estimated 4,000 deaths.Historians such as David Stannard and Barbara Mann have noted that the army deliberately routed the march of the Cherokee to pass through areas of a known cholera epidemic, such as Vicksburg. Stannard estimates that during the forced removal from their homelands, following the Indian Removal Act signed into law by President Andrew Jackson in 1830, 8,000 Cherokee died, about half the total population.United States acquisition of California
The U.S. colonization of California started in earnest in 1845, with the Mexican–American War. With the 1848 Treaty of Guadalupe Hidalgo, it gave the United States authority over 525,000 square miles of new territory. In addition to the Gold Rush slaughter, there was also a large number of state-subsidized massacres by colonists against Native Americans in the territory, causing several entire ethnic groups to be wiped out. 
In one such series of conflicts, the so-called Mendocino War and the subsequent Round Valley War, the entirety of the Yuki people was brought to the brink of extinction. From a previous population of some 3,500 people, fewer than 100 members of the Yuki tribe were left. According to Russell Thornton, estimates of the pre-Columbian population of California may have been as high as 300,000. 
By 1849, due to a number of epidemics, the number had decreased to 150,000. But from 1849 and up until 1890 the Indigenous population of California had fallen below 20,000, primarily because of the killings. At least 4,500 California Indians were killed between 1849 and 1870, while many more perished due to disease and starvation. 10,000 Indians were also kidnapped and sold as slaves. In a speech before representatives of Native American peoples in June 2019, California governor Gavin Newsom apologized for the genocide. Newsom said, "That's what it was, a genocide. No other way to describe it. And that's the way it needs to be described in the history books."One California law made it legal to declare any jobless Indian a vagrant, then auction his services off for up to four months. It also permitted whites to force Indian children to work for them until they were eighteen, provided that they first obtain permission from what the law referred to as a 'friend'. Whites hunted down adult Indians in the mountains, kidnapped their children, and sold them as apprentices for as little as $50. Indians could not complain in court because of another California statute that stated that 'no Indian or Black or Mulatto person was permitted to give evidence in favor of or against a white person'. 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". The towns of Marysville and Honey Lake paid bounties for Indian scalps. Shasta City offered $5 for every Indian head brought to City Hall; California's State Treasury reimbursed many of the local governments for their expenses.