Mambo, the music, as we know it dates to about 1938 when Oresta Lopez composed a danzon he called the "Mambo." He combined danzon with African rhythms from the street. The dancing itself came out of rehearsals where couples improvised steps to the new beat. In the 1950s, Mambo was popularized as a specific musical genre when Perez Prado began to market his music under the name "mambo" - he was the first and many others followed. Prado took his music to New York via Mexico and basically commercialized the music by changing it to suit his "white" audience. If you listen to Prado's music and compare it to other Cuban artists of the day you'll find it contains a lot of influences outside of the Cuban tradition and to my mind is lacking something - emotion. Still, it must be recognized that it was he who first popularized the music in North America and Europe.