Berthelot was among the earliest French surnames established in the Louisiana colony. At least three individuals of that name came to the Mobile area before 1720,* but only one-Urbain Berthelot (m. Marie LeMire), probably a soldier in the French Army-appears to have been the progenitor of the Berthelot families now living in Louisiana.

His son, Jean-Louis (b. 1720 at Ft. Louis, Mobile), also a soldier, married ca. 1742 Louise Fontenot, who gave birth to three known sons-Henri, Yves, and Pierre-and one daughter-Marie-Thérèse.

After 1763, when England was given West Florida, the Berthelots, together with many other Gulf Coast French, migrated to Louisiana, where they settled along the Second German Coast (St. John Parish) with some of their Fontenot and Brignac relatives.

Sons Henri (m. 1779 Catherine Loupe) and Yves (m. 1783 Marie Loupe) remained along the Mississippi River; their brother Pierre (m. 1784 Anne-Barbe Kerner), however, eventually moved to Bayou Lafourche and their sister, Marie-Thérèse (m. François Stelly) migrated to the Opelousas area.

Yves and his descendants made St. John Parish the main center of the Berthelot family in Louisiana during the late eighteenth and for most of the nineteenth centuries.

His four sons-Jean-Baptiste (m. 1817 Marguerite Barbier), Firmin (m. 1817 Josephine Cosse), Benjamin (m. 1820 Marcelitte Schexnayder), and Pierre (m. 1829 Arthémise Broussard) produced large families, most of whom probably were farmers of fair means on the west bank of the Mississippi near Edgard.

At least one of Yves's descendants, Paul Berthelot, a grandson of Firmin, became a prominent state legislator in the late nineteenth century and in 1886 purchased the Lucy Plantation below Edgard.

Henri Berthelot remained in St. John Parish until 1807 or 1808, when he moved his family upriver into St. James Parish.

There he established himself as a planter on the east bank of the Mississippi, and by 1820 possessed 36 slaves as house and field workers.

His sons Henri, Jr.

(m. 1805 Scholastique Villique or Willig) and Jean-Louis (m. 1817 Séraphine Webre) and their descendants carried on the Berthelot name in St. James during antebellum times, especially near Convent.

After the Civil War possibly some of them migrated inland to Livingston Parish, which by 1880 contained six Berthelot familes along the lower Amite Rive,11 probably ancestors of those who live there today. By 1880 at least one Berthelot family, possibly of Henri's line, resided in Ascension Parish.

Later in the decade Victor Berthelot and his brother "J. A." (sons of Pierre Berthelot and Angèle Lorio) acquired the Chatham and Claiborne plantations — some 2,700 acres-in Ascension and Iberville parishes, forming one of the largest cane-growing companies in the area.

Pierre, the younger member of the Mobilian Berthelots, after residing several years near his brothers in St.

John Parish, in 1794 moved his family to Bayou Lafourche, settling on a 7 x 40 arpent tract he had purchased near present Thibodaux.

There his three sons-Jean-Pierre (m. 1818 Aspasie Lagrange, 1826 Rosalie Hébert), André-Marcelin (m. 1821 Eugénie Boudreaux, 1828 Félicité Hausnoff), and François-Firmin (m. 1830 Aglae Hébert) reared large families.

Before the Civil War, however, the Berthelots of Lafourche began to decline drastically in numbers, possibly because of migrations out of the area for which there appears to be scant documentation.

Today only seven Berthelot households remain along the Lafourche