Probably all Prejean families living in Louisiana today can look to Acadia for their ancestral roots. In 1765 four brothers of that surname, sons of Joseph Préjean and Marie-Louise Comeaux of Chipoudy, Acadia, reached Louisiana with one of the several Acadian exile groups arriving that year.* All four brothers-Amand, Joseph, Charles, and Basile-were assigned lands on the west bank of the Mississippi, probably near present Donaldsonville, in Ascension Parish.

For reasons unknown both Amand and Charles soon left the Mississippi River to resettle in the Attakapas,3 whereas Joseph and Basile remained on their original holdings in Ascension. In the early 1800s, however, one of Joseph's sons, also called Basile, moved into the Thibodeauxville area to begin the Lafourche branch of the Prejean family.

Amand Préjean, the elder of the four brothers, arrived in Louisiana with his wife Madeleine Martin, three sons (Marin, age 15 or 16; Joseph, age 5, and André, an infant born at sea in 1765) and two teenage daughters.

After settling in the colony he fathered three more daughters by Madeleine and by his second wife, Marie Thériot, three additional children, including a son, Dominique.

Arriving in the Attakapas probably in 1766 or 1777,7 Amand, and later his four sons, were responsible for the beginning of the Teche-Opelousas branch of the Prejean family, which today comprises almost half of all households of that name in Louisiana. In 1778 Amand received from the Spanish authorities a grant of land of some 425 acres fronting on Bayou Vermilion in the Grande Prairie of the Attakapas.

Judging from later descriptions of land claims made by some of Amand's sons, the grant was situated just to the east of Carencro and about five miles north of present Lafayette.

Church records indicate that the Carencro area remained the chief center of Prejean families in the state throughout the nineteenth century10 and probably well into the twentieth. However, before the Civil War a few of Armand's male-line descendants had migrated to the Plaisance area north of Opelousas (e.g., great-grandsons Édouard-Ursin and Gérasim Prejean) and southward to the vicinity of Abbeville in Vermilion Parish (e.g., great-grandsons André-Valérien and Odilon Prejean).

Movement of Prejeans into southwestern Louisiana and southeastern Texas probably did not occur until after World War I . These migrants were likely all descendants of Amand, since the male line of his brother Charles (m. ca. 1766 Marguerite Richard) apparently died out in the early 1800s.

As mentioned above, the Lafourche branch of the family was started by a son of Acadian Joseph Préjean — Basile (m. 1792 Rosalie Lachaussé), who in the late 1810s moved from Ascension Parish to settle along Bayou Lafourche in the vicinity of Thibodeauxville.

In the 1850s some of his descendants were found along Bayou Terrebonne near Houma, and by the 1880s at least one of his grandsons, Eugène-Louis (m. 1850 Marie Kelley) had reached the Larose area along the lower Lafourche.

Little is found in the published church records regarding other descendants of the Acadian Prejean brothers, Joseph and Basile, most of whom probably remained along the Mississippi River near Donaldsonville or along the upper portion of Bayou Lafourche in Assumption Parish