The Bridge Wars was a hip hop rivalry active during the late 1980s, primarily involving KRS-One of Boogie Down Productions and MC Shan of Juice Crew. The dispute concerned territory in New York City: it began with Queensbridge-based Marley Marl and MC Shan's song "The Bridge" in late 1985, in which they sung the praises of their home borough and loosely implied that Queensbridge was where hip hop began. Taking offense to this, South Bronx-based KRS-One and Boogie Down Productions released the song "South Bronx", which was identical in terms of content to Shan and Marl's song except that they sang the praises of South Bronx instead of Queensbridge, making the argument that the true home and birthplace of hip hop was in the South Bronx. The Juice Crew soon responded with the song "Kill the Noise" on Shan's album Down by Law, which took various shots at KRS-One and mocked him taking offence in the first place. KRS's main response was the Jamaican-influenced "The Bridge Is Over". Most of KRS's fire was directed at Marley Marl and MC Shan specifically, though he occasionally exchanged insults with other Juice Crew members such as Mr. Magic and Roxanne Shanté. Roxanne responded with a song aimed at Boogie Down Productions entitled "Have a Nice Day", which was later remixed and released on her 1989 album Bad Sister.
The feud calmed down temporarily when Boogie Down Production's DJ Scott La Rock was shot and killed in 1987 after attempting to defuse a situation. After KRS-One started the Stop the Violence Movement, he had his attention elsewhere, and the Juice Crew, out of respect, stopped releasing diss records until 1989. In that year, MC Shan attempted to restart the rivalry on his song "Juice Crew Law" which contained several shots at KRS. It took KRS more than a year to respond, but he eventually did on his song "Black Man in Effect" from the 1990 album Edutainment.
During the 1990s, the rivalry was fondly remembered by fans and participants as a classic hip hop duel. MC Shan and KRS-One acknowledged the beef's importance in hip hop history when they appeared together in a commercial for the Sprite soft drink in the mid-nineties, where they exchanged battle rhymes inside of a boxing ring. MC Shan, widely seen by hip hop fans as the loser of the feud, never recovered his reputation and effectively retired. KRS lived out a successful solo career and remained an important figure in hip hop.