At some time in the late 23rd century, the Acamarians ceased their traditional history of clan rivalries and violent feuding. They had since enjoyed continual peace through 2366. The exception to this was a splinter group known as the Gatherers, who refused to be a part of the peace settlement and thus lived off-world as nomadic interstellar marauders. A commonly-held belief blamed the Gatherers for numerous raids on outposts and ships in the sector near Acamar III.
Distinguishing external physical traits of the Acamarians included a formed indentation on their foreheads and traditional facial tattoos. Acamarian blood comprised an iron and copper base, a rarity among species in that area of the galaxy.
Acamarian culture placed much importance on clan membership, both in society and politics. Before establishing peace, inter-clan warfare was notoriously violent. One such feud, between the Lornak and the Tralesta clans, lasted almost three centuries and ended only after the (presumed) annihilation of the Tralesta clan.
In 2366, the head of the Acamarian government was Sovereign Marouk. In that year, she offered repatriation for the estranged Gatherers, as mediated by Captain Jean-Luc Picard; negotiations to reunite the Acamarians and the Gatherers took place at a Gatherer camp on Gamma Hromi II. Despite some difficulties, including mutual distrust and an assassination attempt on the Gatherer leader, Picard was eventually successful, and the Gatherers agreed to return home the same year. (TNG: "The Vengeance Factor")