The Jacobites were one of the lineage groups among the followers of Nephi, named after Jacob, the brother of Nephi who founded the Nephite nation. Jacob lists them in his record among seven divisions of Lehi’s descendants: Nephites, Jacobites, Josephites, Zoramites, Lamanites, Lemuelites, and Ishmaelites (Jacob 1:13).
In the same passage Jacob states that he will no longer distinguish the people by these tribal names, calling those who sought to destroy the people of Nephi Lamanites, and those friendly to Nephi he would call Nephites (Jacob 1:14). Despite this, the Jacobites continued to be named as a distinct group in the later record.
After Christ’s ministry among Lehi’s descendants, the name reappears: those who became true believers in Christ were called Nephites, Jacobites, Josephites, and Zoramites, the tribal labels having been applied to them by the Lamanites (4 Nephi 1:36-37).
The Jacobites are named a final time at the outbreak of the war between the Nephites and Lamanites, when the Nephite side consisted of the Nephites, Jacobites, Josephites, and Zoramites (Mormon 1:8). The record gives no individual Jacobites or activities beyond the tribal name.