Post-hardcore is a genre of music that is derived from and has origins in the hardcore punk music genre, itself an offshoot of the broader punk rock movement. Like post-punk, post-hardcore is a term for a broad constellation of groups. Many emerged from the hardcore punk scene, or took inspiration from hardcore, while concerning themselves with a wider degree of expression.
The genre took shape in the mid-to-late-1980s with releases from bands from cities that had established hardcore punk scenes, in particular from the scenes in Washington, D.C. such as Fugazi as well as slightly different sounding groups such as Big Black and Jawbox that stuck closer to the noise rock roots of post-hardcore.
(Wikipedia contributors. “Post-hardcore.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 14 Jul. 2014. Web. 28 Jul. 2014.)