Although not often thought of as an “Acadian Parish,” West Baton Rouge was profoundly influenced by the arrival of the Acadians. In 1785, seven ships came from Spain to Louisiana, bearing Acadian refugees. Several of these seven ships, the Beaumont, Le Bon Papa, La Villa de Arcangel, and La Carolina, bore Acadian families who ended up settling in what would become West Baton Rouge Parish. Acadian families who settled in the area include the Babin, Benoit, Bourg, Caillouet, Comeaux, Daigle, Doiron Dubois, Duput, Dugas, Giroire, Guedry (Guidry), Granger, Hébert, Labauve, Leblanc, Martin, Poirier, Richard, Templet, Theriot, and Trahan families. Descendants of these Acadian settlers still live in West Baton Rouge Parish today.
Among these Acadian arrivals was Jacques Molaison, a 38-year-old carpenter, his wife Marie Doiron, and their three children. In 1785, Jacques Molaison received a Spanish land grant in the area that now makes up West Baton Rouge Parish, built a store, and went into business. A village developed around his land, which was called Molaisonville, and is recognized as the oldest settlement in the parish. Molaisonville was later renamed Brusly Landing, and served as a landing for steamboats that stopped to pick up cotton grown in the area. The village was officially incorporated in 1901 with the simplified name of Brusly.
Brusly Landing had already been established in the southern part of the parish. The first recorded settlement on the site that is now Port Allen was the town of St. Michel. A French doctor, Michel Mahier, provided the land and layout for this town. Mahier had been working for the Spanish government as a physician at the Royal Hospital in Louisiana since approximately 1792, originally for the District of Manchac and then for the District of Baton Rouge. He owned and operated a planation on the west side of the river. He also used some of the land to develop a town: la ville de St. Michel. He laid out five blocks of streets, lots, and public spaces, and began selling the first lots in 1809, but died shortly thereafter. His wife, Marie Francoise Sigorlot then carried on his work until her death in 1822.
Erosion of the banks caused by the Mississippi River destroyed much of the town by the 1820s, but some lots survived until the 1860s. Another town was laid out in 1854 by Wing W. Kinchloe. The area, called simply the Town of West Baton Rouge, extended approximately 3½ blocks to the river next to the surviving commercial strip of St. Michel.