Niger-Congo is a hypothetical language family spoken over the majority of sub-Saharan Africa.[1] It unites the Mande languages, the Atlantic-Congo languages (which share a characteristic noun class system), and possibly several smaller groups of languages that are difficult to classify. If valid, Niger-Congo would be the world's largest in terms of member languages, the third-largest in terms of speakers, and Africa's largest in terms of geographical area.[2] It is generally considered to be the world's largest language family in terms of the number of distinct languages,just ahead of Austronesian.

Origin.
The language family most likely originated in or near the area where these languages were spoken prior to Bantu expansion (i.e. West Africa or Central Africa). Its expansion may have been associated with the expansion of Sahel agriculture in the African Neolithic period, following the desiccation of the Sahara in c. 3500 BCE.
According to Roger Blench (2004), all specialists in Niger–Congo languages believe the languages to have a common origin, rather than merely constituting a typological classification, for reasons including their shared noun-class system, shared verbal extensions and shared basic lexicon.
https://en.wikipedia.org/wiki/Niger%E2%80%93Congo_languages

QueenNyakim:
In the top 10 with 200 million speakers and pretty much the lingua franca of East Africa with many other African countries adopting language and making it mandatory to learn in school such as Botswana, Egypt, South Africa, DRC etc. AU has even adopted Swahili as the official working languages.

Its a smexy language and I am learning it, why not abandon the colonizers language as the lingua franca of Africa and adopt one of Africa's indigenous Bantu ones like Swahili to conduct business in the continent? Only 15% of Swahili is made up of loan words from Arabic, Portuguese, British etc.

This been said, Swahili is not an authentic African language like Hausa, Wolof, Igbo, Yoruba, Ashanti, Guere,
Mande, Susu, Gerhze etc. It is mixed with too much Arabic.

panafrican:
You can speak Haussa, Yoruba and Igbo, Sussu, Bambara, Kpelle , etc. without using any
English word. You can't when it comes to Swahili and Arabic.