The modern banjo derives from instruments that had been used in the Caribbean since the 17th century by enslaved people taken from West Africa. Written references to the banjo in North America appear in the 18th century, and the instrument became increasingly available commercially from around the second quarter of the 19th century.
Several claims as to the etymology of the name "banjo" have been made. It may derive from the Kimbundu word mbanza, which is an African string instrument modeled after the Portuguese banza: a vihuela with five two-string courses and a further two short strings. The Oxford English Dictionary states that it comes from a dialectal pronunciation of Portuguese bandore or from an early anglicisation of Spanish bandurria. The name may also derive from a traditional Afro-Caribbean folk dance called "banya", which incorporates several cultural elements found throughout the African diaspora.
The Portuguese banza: a possible ancestor of the modern banjo
Various instruments in Africa, chief among them the kora, feature a skin head and gourd (or similar shell) body. The African instruments differ from early African American banjos in that the necks do not possess a Western-style fingerboard and tuning pegs, instead having stick necks, with strings attached to the neck with loops for tuning. Banjos with fingerboards and tuning pegs are known from the Caribbean as early as the 17th century. Some 18th- and early 19th-century writers transcribed the name of these instruments variously as bangie, banza, bonjaw, banjer and banjar. Instruments similar to the banjo (e.g., the Japanese shamisen, Persian tar, and Moroccan sintir) have been played in many countries. Another likely relative of the banjo is the akonting, a spike folk lute played by the Jola tribe of Senegambia, and the ubaw-akwala of the Igbo. Similar instruments include the xalam of Senegal and the ngoni of the Wassoulou region including parts of Mali, Guinea, and Ivory Coast, as well as a larger variation of the ngoni developed in Morocco by sub-Saharan Africans known as the gimbri.
Early, African-influenced banjos were built around a gourd body and a wooden stick neck. These instruments had varying numbers of strings, though often including some form of drone. The five-string banjo was popularized by Joel Walker Sweeney, an American minstrel performer from Appomattox Court House, Virginia.
Although Robert McAlpin Williamson is the first documented white banjoist, in the 1830s, Sweeney became the first white performer to play the banjo on stage. His version of the instrument replaced the gourd with a drum-like sound box and included four full-length strings alongside a short fifth string. This new banjo was at first tuned d'Gdf♯a, though by the 1890s, this had been transposed up to g'cgbd'. Banjos were introduced in Britain by Sweeney's group, the American Virginia Minstrels, in the 1840s, and became very popular in music halls.
In the antebellum South, many black slaves played the banjo and taught their masters how to play. For example, in his memoir With Sabre and Scalpel: The Autobiography of a Soldier and Surgeon, the Confederate veteran and surgeon John Allan Wyeth recalls learning to play the banjo as a child from a slave on his family plantation.