While Grandmaster Flash & The Furious Five was the first to release a well-known political rap single called "The Message" in 1982, New York-based Public Enemy is considered one of the first mainstream political rap group and one of the most influential hip-hop groups of all time.
At their prime in the late 1980s/early 1990s, PE thrived on expressing their points of views on socio-economic issues -- even if their fans didn't always agree -- and getting listeners to think. Their album, "Fear of a Black Planet," would become one of the top politically-driven hip-hop albums for generations to come.
Political rap became most popular around the same time gangster rap hit the scene, with groups like N.W.A. spearheading that movement. Although both groups rapped about similar topics -- drugs, crime, racism, poverty -- there was a notable difference: gangster rappers rhymed in the first person, from their own experiences, about their own hardships growing up in the inner city hoods. N.W.A.'s "Straight Outta Compton" album would go on to be considered one of the best gangsta rap albums.