In the period 1900-1910 18 million acres of tribal lands were taken by the US government through the policy of forced allotments and sale of surplus land. Indian economies were destroyed and tribal leadership devastated.
In 1906 Congress amended the Allotment Act eliminating the 25-year trust period. As a result the Secretary of the Interior could issue fee-simple title to any Indian allottee deemed competent and capable to manage his or her affairs. Once the title has been received the land could be sold. This made more Indian land available for sale or lease.
In 1917 the Indians who were not allowed to vote in the USA were encouraged to engage in the armed services. “Citizen Indians” were those who had taken an allotment and kept it for 25 years or who had received a “certificate of competency” from the secretary of the Interior and were subject to conscription. After draft registration for all Indian males took place on June 1917 there were protests in many reservations. The Goshiute protested so much that the government had to send some troops in Utah. They said that they were not US citizen since they could not vote and that only “citizen Indians” were subject to the draft. However they were considerable pressures to enlist and at least 10,000 Indian men enlisted. The First World War created many job opportunities for the Indians but only at low level and very little in war industries.
There was a campaign to grow more food for the war effort and, as a result, there was large-scale leasing of Indian lands to white farmers. The Crow were told to lease 5,000 acres; the Shoshone, Blackfoot and Crow reservations had to lease 200,000 acres; the Pine Ridge reservation had also to lease much of its lands.
In 1919, all Indians who had served in the Armed Forces were granted full citizenship by Congress.
In 1920 the Indian population began to increase from its low point of 250,000 at the end of the 19th century. However life expectancy was still around 40 years on most reservations and infant mortality was twice that of the rest of the USA. The level of education on the reservations was also low and unemployment could reach 75% in some reservations.
The Indian Oil Leasing Act passed by Congress in 1924 dropped the 10-year limit for leases and allowed them to run for as long as the oil did. It also allowed the states to tax production on the reservations. An amendment gave the states 37.5% of revenues; These moneys should be spent on Indian education and roads but most tribes had no central authority to manage the money so it did not go to the Indians. In many cases state taxes on mining production on Indian reservations were higher that the royalties received by the tribes.
In 1924 the Indians became US citizens and could vote in national elections. However in many states like Arizona and New Mexico they could not vote in state or local elections because of their federal trust relationship and special status under federal law.
In 1938 Congress passed the Indian Lands Mining Act that allowed the secretary of the interior broad power over mineral development on Indian lands including the right to issue ten-year leases on any Indian lands.
In 1941-1945 all Native American men were required to register for the draft although they could not still vote in many states. Around 24,500 Native American served in the US armed services in World War II. Quite a few southwestern Indians served in a National Guard unit sent to the Philippines where they were captured by the Japanese.
Termination became the official American Indian policy in the period 1953-1962. during that time 13 tribes were terminated the largest one being the Menominees in Wisconsin, the Klamaths in Oregon as well as at least one hundred bands, communities and Rancherias loosing many federal protection and services. Termination generally meant that the tribes involved lost trust status and were obliged to pay taxes for which they often had to sell parts of their remaining lands. They also had to provide and fund their own education and health services.
The National Congress of American Indians met in Chicago in 1961 and sa9d that termination was the greatest threat to Indian survival since the 1800s military actions. Also the same year President Kennedy appointed a task force on Indian Affairs who recommended the termination of the policy of termination.
In 1970 President Nixon formally brought the termination policy to an end. He announced a new federal policy of Indian self-determination without terminating of federal services.
In 1979 the American Indian religious Freedom Act became law. It said that Indian religions were protected under the First Amendment of the US Constitution.
The 1980 US Federal Census found that there were now almost 1.5 million Native Americans.