Ignoring the service of Delaware and Shawnee to the Union, the Kansas legislature in 1863 called for the removal of all Indians from Kansas.
On July 4th, 1866 the Delaware signed their final treaty with the United States which allowed the Secretary of the Interior to sell their remaining Kansas lands to the Missouri River Railroad Company.
Individual Delaware, if they wished, could keep their 80 acre allotments and become American citizens, but in a situation reminiscent of the burnings in the Wyoming Valley in 1763, the Delaware Council House mysteriously burned afterwards. Most Delaware took the “hint,” and of the 1,160 Delaware in Kansas, 985 of them decided to move to Oklahoma.
The main body of Lenape arrived in the northeast region of Oklahoma in the 1860s. Along the way many smaller groups left, or were told to stay where they were. Consequently today, from New Jersey to Wisconsin to southwest Oklahoma, there are groups who retain a sense of connection with ancestors who lived in the Delaware Valley in the 17th century and with cousins in the Lenape diaspora.
The two largest groups are the Delaware Nation (Anadarko, Oklahoma), and the Delaware Tribe of Indians (Bartlesville, Oklahoma), the only two federally recognized Lenape (Delaware) tribes in the United States.
The Oklahoma branches were established in 1867.
The Delaware were required to purchase land from the reservation of the Cherokee Nation; they made two payments totaling $438,000.
A court dispute followed over whether the sale included rights for the Delaware as citizens within the Cherokee Nation.
While the dispute was unsettled, the Curtis Act of 1898 dissolved tribal governments and ordered the allotment of tribal lands to individual members of tribes. After the lands were allotted in 160-acre (650,000 m²) lots to tribal members in 1907, the government sold “surplus” land to non-Indians. It soon became obvious that the land was not suitable for subsistence farming on such small plots.
In 1979, the United States Bureau of Indian Affairs revoked the tribal status of the Delaware living among Cherokee in Oklahoma.
They began to count the Delaware as Cherokee. The Delaware had this decision overturned in 1996, when they were recognized by the federal government as a separate tribal nation.
The Cherokee Nation filed suit to overturn the recognition of the Delaware. The tribe lost federal recognition in a 2004 court ruling in favor of the Cherokee Nation, but regained it on 28 July 2009.
After recognition, the tribe reorganized under the Oklahoma Indian Welfare Act. Members approved a constitution and bylaws in a May 26, 2009 vote.