information:filtering, structural:reformatting, stylistic:style_transfer
History of the proposal

The Saharan family (which includes Kanuri, Kanembu, the Tebu languages, and Zaghawa) was recognized by Heinrich Barth in 1853, the Nilotic languages by Karl Richard Lepsius in 1880, the various constituent branches of Central Sudanic (but not the connection between them) by Friedrich Müller in 1889, and the Maban family by Maurice Gaudefroy-Demombynes in 1907. The first inklings of a wider family came in 1912, when Diedrich Westermann included three of the (still independent) Central Sudanic families within Nilotic in a proposal he called Niloto-Sudanic; this expanded Nilotic was in turn linked to Nubian, Kunama, and possibly Berta, essentially Greenberg's Macro-Sudanic (Chari–Nile) proposal of 1954.

In 1920 G. W. Murray fleshed out the Eastern Sudanic languages when he grouped Nilotic, Nubian, Nera, Gaam, and Kunama. Carlo Conti Rossini made similar proposals in 1926, and in 1935 Westermann added Murle. In 1940 A. N. Tucker published evidence linking five of the six branches of Central Sudanic alongside his more explicit proposal for East Sudanic. In 1950 Greenberg retained Eastern Sudanic and Central Sudanic as separate families, but accepted Westermann's conclusions of four decades earlier in 1954 when he linked them together as Macro-Sudanic (later Chari–Nile, from the Chari and Nile Watersheds).

Greenberg's later contribution came in 1963, when he tied Chari–Nile to Songhai, Saharan, Maban, Fur, and Koman-Gumuz and coined the current name Nilo-Saharan for the resulting family. Lionel Bender noted that Chari–Nile was an artifact of the order of European contact with members of the family and did not reflect an exclusive relationship between these languages, and the group has been abandoned, with its constituents becoming primary branches of Nilo-Saharan—or, equivalently, Chari–Nile and Nilo-Saharan have merged, with the name Nilo-Saharan retained. When it was realized that the Kadu languages were not Niger–Congo, they were commonly assumed to therefore be Nilo-Saharan, but this remains somewhat controversial.

Progress has been made since Greenberg established the plausibility of the family. Koman and Gumuz remain poorly attested and are difficult to work with, while arguments continue over the inclusion of Songhai. Blench (2010) believes that the distribution of Nilo-Saharan reflects the waterways of the wet Sahara 12,000 years ago, and that the protolanguage had noun classifiers, which today are reflected in a diverse range of prefixes, suffixes, and number marking.