Macro-Siouan languages
In the 19th century, Robert Latham suggested that the Siouan languages are related to the Caddoan and Iroquoian languages. In 1931, Louis Allen presented the first list of systematic correspondences between a set of 25 lexical items in Siouan and Iroquoian. In the 1960s and 1970s, Wallace Chafe further explored the link between Siouan and Caddoan languages. In the 1990s, Marianne Mithun compared the morphology and syntax of all the three families. At present, the Macro-Siouan hypothesis based on relations among Siouan, Caddoan, and Iroquoian is not universally accepted as proven.
Monacan people
The contemporary Monacan people claim descent from the historic Monacan tribe, first recorded in 1607 in Virginia. They originally spoke a Siouan language and were related to other Siouan-speaking tribes, such as the Tutelo, Saponi and Occaneechi. Today the people speak English.