Although Pieces of Her takes place in 2018 and 1986, the novel references many historical events and figures from the 1960s and 1970s. The Army of the Changing World, the group run by Nick Harp, identifies itself as an activist group, and sees their activities as efforts to force the United States to make changes to its systems. But their actions are those of a terrorist group, and their structure and operations parallel those of a cult. The novel references many organizations and leaders from the 1960s and 1970s to reinforce Karin Slaughter’s depiction of the Army of the Changing World.

One such organization is the Weather Underground, an infamous domestic terrorist group which operated in the United States during the 1970s. The group orchestrated several bombings in an effort to disrupt and dismantle the US government. The activities of the Army of the Changing World in Pieces of Her imitate the activities of the Weather Underground more so than any other group.

Slaughter also references historical examples of cults and cult leaders to deepen the reader’s understanding of the Army of the Changing World. These references build on one of the themes of the novel, which considers whether or not Nick’s group is, in fact, a cult.