Siouan languages
Siouan languages can be grouped into the Western Siouan languages and Catawban languages. The Western Siouan languages can be divided into Missouri River languages (such as Crow and Hidatsa), Mandan, Mississippi River languages (such as Dakotan, Chiwere-Winnebago, and Dhegihan languages), and Ohio Valley Siouan branches. The Catawban languages consist only of Catawban and Woccon.
Isan language
Isan speakers became politically separated from other Lao speakers after the Franco-Siamese War of 1893 would lead Siam to cede all of the territories east of the Mekong to France, which subsequently established the French Protectorate of Laos. In 1904, Sainyabuli and Champasak Provinces were ceded to France, leading to the current borders between Thailand and Laos. A 25 km demilitarised zone west of the river banks allowed for easy crossings, and Isan remained largely neglected for some time. Rebellions against Siamese and French incursions into the region included the Holy Man's Rebellion (1901-1904), led by self-proclaimed holy men. The Lao people also joined in the rebellion, but was crushed by Thai troops in Isan. At first, Isan was administered by Lao local rulers subject to the Siamese Court under the monthon system of administration, but this was abolished in 1933, bringing Isan under the direct control of Bangkok.