De exámenes y ratos de recreo

In Buenos Aires, however, Africans lived and worked together, and formed cabildos and cofradías based on individual ethnic groups. As in Uruguay, black Argentines fought in large numbers in the wars of colonial independence. Many became gauchos, and some of the best song improvisers or payadores were African origin. Black gauchos appear in Gaucho literature, from Martin Fierro to Santos Vega. Following the abolition of slavery and independence from Spain, Afro-Argentines freely organized dances and carnival comparsas, bringing their language and culture before the masses of Argentine society [...] Although most blacks lived marginally, working as labourers, itinerant vendors, servants, coachmen and the like, they were everywhere in Buenos Aires, and their tango originated among Africans in the River Plate region, although the word itself had previously been used in Andalusia. The typically River Plate word mucama "female domestic servant" is also of African origin.

John Lipski, Latin American Spanish.