Although post-hardcore is primarily rooted in post-punk and hardcore punk, the music that created the space for it were groups like Black Flag, The Minutemen, Flipper and Hüsker Dü, who proved there was indeed room for stylistic diversity in hardcore punk, and abrasive art punk units like Sonic Youth and Big Black, who had arrived too late to truly be part of the initial post-punk movement. Unlike post-punk, post-hardcore was almost exclusively an American phenomenon.

Post-hardcore developed due to not only the stylistic limitations of hardcore punk, but also as an effort directly alienate the boorish, violent culture that had grown around hardcore punk much to the ire of the influential figures. The earliest appearances of post-hardcore itself were in Washington, D.C. and the surrounding Maryland area in the mid-1980s, thanks largely to a 1985 campaign by Washington's Dischord records called Revolution Summer, which aimed to break the label and its followers free from the creative and social dead-end of hardcore punk. The first post-hardcore, played by bands like Rites of Spring, Embrace, Gray Matter, and Ignition essentially combined a stronger command of songwriting, a better sense of melody and rhythm, and an introspective lyrical focus, with the power of hardcore. Notably, this music was deemed "emocore" by its detractors.

Post-hardcore would not develop its art rock qualities until about 1987, with the arrival of bands including Moss Icon, who would frequently subvert traditional songwriting styles, make use of improvisational techniques and featured an instrumental style influenced as much by groups like Bauhaus and The Cure as it was by Black Flag. Also noteworthy were Happy Go Licky, a reconvening of Rites of Spring who played an updated version of no wave, and Soulside, who emphasized the power of the rhythm section.

Meanwhile, in the northern Midwest a different type of post-hardcore was developing in the wake of the breakup of Big Black, centered around Touch and Go records. Whereas post-hardcore in the DC/Maryland vein was concerned with energy and emotional expression, artists including The Jesus Lizard, Arcwelder, Silverfish and Big Black frontman Steve Albini's own Rapeman and later project Shellac were focused on confrontation through precision and extreme volume. This type of post-hardcore might be less renown than that emanating from Washington, though it lead to the creation of math rock and noise rock and undoubtedly shaped the face of post-hardcore in general as much as the groups from Washington did.

The most influential post-hardcore group of all, though, was Fugazi. Formed in the late 1980s by Dischord founder and Embrace singer Ian MacKaye, along with members of Rites of Spring, Fugazi combined a persistent work ethic with constant stylistic innovation. Fugazi played throughout the 1990s and toured throughout the industrialized world, and in their wake came exciting new labels like Gravity, Ebullition, and Gern Blandsten, and artists such as Native Nod, Clikatat Ikatowi, Hoover, Drive Like Jehu, Navio Forge, Unwound, Maximillian Colby, Lungfish and 1.6 Band, among myriad others. Some groups, most notably Jawbox and Sunny Day Real Estate, were even accessible enough to find a degree of mainstream success.

By the turn of the new millennium, post-hardcore bands including Les Savy Fav, At The Drive-In, and The Dismemberment Plan were openly flirting with elements of dance music, and progressive rock, sometimes even adding electronic instrumentation. The music these groups produced was increasingly lush, and indeed many of them did develop major label affiliations. However, post-hardcore more or less collapsed in the early 2000s, with the break-up of many key artists.