The original Rainbow Coalition formed long before Jesse Jackson's efforts in the early eighties. This movement began in Chicago during the late 1960s through an alliance between The Black Panther Party, the Young Lords Party, and the Young Patriots Organization. The documentary American Revolution II: Right On tells the unique story of this community-based collection of individuals who rapped revolution and transcended all stereotypes.
The Young Lords were a collection of Puerto Rican-Americans inspired by the Black Panthers while the Young Patriots Organization were comprised of mostly poor white people from the south who found solidarity with the Black Panthers and the Young Lords. Black Panther Bobby Lee speaks about this here.