The Medora site, a Plaquemine culture mound site located adjacent to Bayou Bourbeaux on the flood plain of Manchac Point, a hair-pin bend of the Mississippi River in the southeast corner of the parish, was instrumental in defining the Plaquemine culture and period.

[8] The company had an eastern terminus on the west bank of the Mississippi River across from Baton Rouge in what later became the City of Port Allen.

A steam ferry boat, the Sunny South, made three trips a day to connect the railroad to Baton Rouge.

After reaching Bayou Grosse-Tete near the village of Grosse Tete, the line turned to the northwest and ran to Livonia in Pointe Coupee Parish, Louisiana, a total distance of twenty-six miles.

[9] The railroad operated up until May 1862 carrying sugar cane, cotton, and Confederate troops, including the Delta Rifles headed by Captain H. M.

[10] When Union force occupied Baton Rouge in May 1862, all rolling stock was sent to the extreme western end of the railroad for safety where it remained for the duration of the war.

[12] The Arkansas suffered failure of its port engine while proceeding upriver during the battle to get into position to attack the USS Essex.

This caused it to veer into the West Baton Rouge bank about 600 feet south of mile marker 223, where it ran hard aground.

The crew of the Arkansas then set the vessel afire and scuttled it to avoid it falling into enemy hands.

[13] The defeated Union army under the command of Major General Nathaniel P. Banks passed through West Baton Rouge Parish on Rosedale Road on its return to New Orleans in May 1864, after the failure of the Red River Campaign.

The conveyance records on file with the Clerk-of-Court of West Baton Rouge Parish show that many plantation properties were sold at sheriff's sale to satisfy debts in the years immediately after the end of the Civil War.

The Baton Rouge, Grosse Tete, and Opelousas Railroad resumed operation after the end of hostilities, but found the economy adverse, because of the devastation in agriculture.

The Texas and Pacific Railway was chartered by the United States Congress in 1871 to build a southern transcontinental railroad.

A junction was established in the southern part of the parish from which a spur line ran twelve miles northward to the west bank of the Mississippi river across from Baton Rouge at a location which was already called "Port Allen".

The Southern Pacific Railroad built a spur line from Lafayette, Louisiana to Anchorage in West Baton Rouge very early in the twentieth century.

[19] The transfer boat was steam-powered and equipped with rails on its deck that allowed passenger and freight railcars to be rolled on and off.

The camp was located on West Baton Rouge Parish property fronting on Sixth Street in Port Allen.

[20] The Cinclare Sugar Mill Historic District is located in West Baton Rouge Parish near Brusly.

West Baton Rouge's location on the Mississippi River plus railroad transportation has made it attractive to heavy industry.

West Baton Rouge Parish has three incorporated areas (Port Allen, Brusly, and Addis) with local police departments.

The West Baton Rouge Sheriff's Department is responsible for law enforcement in all of the unincorporated areas.