Jaime Escalante came to the US as an emigre from Bolivia, worked at the Burroughs Corporation and later became a math teacher in the LA schools. He famously taught calculus in barrio hellhole Garfield High School and inspired his students to overcome their disadvantages through hard work, discipline, and education. His success engendered disdain and jealousy, he clashed with administrators and had no support from the teachers union, and after his departure the Garfield program eventually collapsed due to lack of institutional support.
At its peak, however, Escalante's determination and hard work helped hundreds of students whose prospects for success would have been minimal without him.
Jaime Escalante, 1930-2010, RIP.