In 2002, Nelly was one of hip-hop's biggest stars. His 2000 breakout debut, Country Grammar, sold nine million records.
Old school boom-bap rap pioneer, KRS-One, who had earned a reputation not just for his community-conscious lyrics but for never shying away from a lyrical showdown, called Nelly out.
KRS— who by that time had already proclaimed himself to be a keeper of classic hip-hop— voiced his discontent with Nelly on the track "Clear Em Out" from the compilation The Difference.
The song was aimed at pop-rap, and given his success as hip-hop's reigning top-seller at the time. Nelly took offense. He'd just dropped the track "#1" from the Training Day soundtrack, where he was defending his right to reign on top of the charts.
"He had to defend himself. He's like, 'My career probably wouldn't be here if it wasn't for KRS-One,' that's what Nelly is on. My man got tired of critics and made a song '#1.' He wasn't specifically talking about nobody, but if the shoe fits, wear it."
KRS claimed he even sent an email to Nelly's camp, explaining there was no beef and he wasn't interested in getting into it with the St. Louis star. Nelly didn't get the memo, however, and in response, recorded a verse on the Freeway's "Roc the Mic" remix, on which he called out the veteran rhymer, letter by letter.
KRS responded by calling for an actual boycott of Nelly's album, Nellyville, which was scheduled to drop that June 2002, dramatically declaring himself a "sovereign power" in the process. Nelly challenged a sovereign power.
Needless to say, the whole boycott thing didn't exactly pan out the way KRS had hoped. June 25, 2002, rolled around, Nelly dropped Nellyville, and the entire world danced to the album's monster hit, "Hot in Herre." Nellyville ended up selling over 6 million albums and it stands as the 14th best-selling rap album of all time.