During these years there was a net immigration of approximately 7,348,000 people into the United States.
During roughly the same period, the population of the country increased by about 27 million people, from about 49 million in 1880 to 76 million in 1900.
Sitting Bull would eventually return to the United States, but he died in 1890 at the hands of the Indian police during the Wounded Knee crisis.
The defeat of the Lakotas and the utterly unnecessary Nez Perce War of 1877 ended the long era of Indian wars.
Following the American defeat at the Battle of the Little Bighorn the previous fall, American soldiers drove the Lakota civil and spiritual leader Sitting Bull and his followers into Canada.
They forced the war leader Crazy Horse to surrender and later killed him while he was held prisoner.
There would be other small-scale conflicts in the West such as the Bannock War (1878) and the subjugation of the Apaches, which culminated with the surrender of Geronimo in 1886, but these were largely police actions.
The slaughter of Lakota Ghost Dancers at Wounded Knee in 1890 did bring a major mobilization of American troops, but it was a kind of coda to the American conquest since the federal government had already effectively extended its power from the Atlantic to the Pacific.
Not satisfied with already ceded lands, reformers—the so-called "Friends of the Indians" whose champion in Congress was Senator Henry Dawes—sought to divide reservations into individual farms for Indians and then open up most or all of the remaining land to whites.
The Dawes Act of 1887 became their major tool, but the work of the Dawes Commission in 1893 extended allotment to the Creeks, Cherokees, Seminoles, Chickasaws, and Choctaws in Indian Territory, which became the core of the state of Oklahoma.