Wilma Rudolph overcame polio as a child (anybody remember polio and the iron lung) and went on to become one of the greatest runners of all time, winning a pile of Olymipic gold medals. It is one of the most amazing stories along these lines I have ever heard. She scores three on the disadvantaged list. Crippled, black and a women. But for athletics as such, it would have to be Babe Ruth hitting 60 home runs.
Al Jolson was probably the first musical superstar in the pop domain. What he was doing was "crossing over" a style of black music (believe it or not) into the mainstream, a lucrative feat performers have since repeated many times over, notably by Elvis Presley. But there is not much doubt that the Beatles were the most amazing "artistic" event to ever hit popular culture.
Euclids writing of "The Elements" has to be the foremost scientific achievement of all time. Although it is a book on geometry, it is so uncannily perfect that its method and presentation is the model and standard all scientific works seek to achieve. Attempts to fix an apparent difficiency in it produced a chain developements that enabled Einstein to formulate the General Theory of Relativity. For technology, the award has to go to CHEAP books, but whether to attribute this more to paper or to the printing press is a hard one. Books still were not cheap until the printing presses got cheap, which took some time and some doing. In the beginning only holy works were consider worthy of this expense. Cheap books lead to an explosion of the availabity of knowledge and information to tremendously larger number of people. That enlarged, but still elite, group of people produced an explosion in invention and technology that is still running exponentially today, and appears to producing another amplifcation of information availability in the Internet.