I see rap as kind of an inevitable evolution of blues actually, but hiphop as a whole is absolutely thanks to jazz. Also, it's arguable but you can thank Miles Davis for bridging a coherent gap between jazz and hiphop with the album Doo-Bop, although he died before it was finished and the guy rapping ruined it a little lol
This one's got to be up there as well in regards to bridging that gap:... Jazz samples have also had a large role in hip-hop, but the idea of rapping over actual live jazz wasn't truly fully realized until Gang Starr MC Guru created and released the first in his Jazzmatazz series in 1993, with guest musicians who included saxophonist Branford Marsalis (who had previously collaborated with DJ Premier and Guru for the track "Jazz Thing" on the Mo' Better Blues soundtrack), trumpeter Donald Byrd, vibraphonist Roy Ayers, guitarist Ronny Jordan, and keyboardist Lonnie Liston Smith, as well as vocalist N'Dea Davenport (also of the acid jazz group the Brand New Heavies) and French rapper MC Solaar. "
(AllMusic)