Reformers persuade Congress to abandon the practice of dealing with Native American tribes as separate nations. A new approach incorporated in the Dawes Act of 1887 is designed to break up tribal organizations, which many feel keep Native Americans from becoming “civilized” and law-abiding citizens. The Dawes Act divides the tribal lands into plots of 160 acres or less, depending on family size. U.S. citizenship is granted to those who stay on the land for 25 years and “adopt the habits of civilized life. "Under the Dawes Act, 47 million acres of land are distributed to Native Americans. What reformers did not anticipate, however, was that 90 million acres of former reservation land—often the best land—would be sold over the years to white settlers by the government, speculators, or Native Americans themselves. The new policy proved a failure. By the turn of the century, disease and poverty had reduced the Native American population to just 200,000 people, most of whom lived as wards of the federal government.The last effort of Native Americans to resist U.S. domination and drive whites from their ancestral lands came through a religious movement known as the Ghost Dance. In the government’s campaign to suppress the movement, the famous Sioux medicine man Sitting Bull was killed during his arrest. Then in December 1890, over 200 Native American men, women, and children were gunned down by the U.S. Army in the “battle”(massacre) of Wounded Knee in the Dakotas. This final tragedy marked the end of the Indian Wars on the crimsoned prairie.