Due to external pressures from federal Indian agents and religious missionaries, as well as internal turmoil, in 1913 the tribe created an advisory committee.

During their 2002 tribal general elections, they approved a measure changing the name to Sisseton Wahpeton Oyate, the latter word in the Dakota language meaning "people or nation".

The territorial governor, Alexander Ramsey, and Commissioner of Indian Affairs, Luke Lea, instigated the treaty to gain concessions of the rich agricultural lands in Minnesota for European-American settlers.

By 1858 Dakota leaders went to Washington D.C. to sign two more treaties, ceding the reservation north of the Minnesota River (whose boundaries had never been approved by the US Congress).

The US Indian Agent and Minnesota State Senator Thomas J. Galbraith refused to distribute supplies without having received payment from the Sioux.

Historians note actions by four Dakota aki-ci-ta (warriors) at a settlement at Acton, Meeker County, as the beginning of the conflict.

A large number of Sisseton and Wahpeton had adopted both subsistence farming and Christianity, and had both moral objections and strong reasons of self-interest for keeping peace with the whites.

[3] Dakota aki-ci-ta laid siege to Fort Abercrombie for six weeks and disrupted supply lines and shipping from the north and Canada, as well as couriers heading to St.

Large-scale combat ended on September 26, 1862 when six companies of Minnesota militia and an artillery unit attacked Dakota positions at the Battle of Wood Lake.

Of the 303, the Army hanged 38 men the day after Christmas in Mankato, Minnesota, in the largest mass execution in United States history.

Soon after, additional conflicts in what were known as the Indian Wars broke out to the south and west, ending finally with the Wounded Knee Massacre in 1890 and the defeat of the Sioux.

In 1993, nearly two decades since tribes had been taking back control of their children's education, this school was chartered under the Sisseton Wahpeton Oyate, whose Lake Traverse Reservation extends into North Dakota.