Tensas Parish (French: Paroisse des Tensas) is a parish located in the U.S. state of Louisiana. The seat of the parish is St. Joseph. In 2010, the population of Tensas Parish was 5,252; it is the least-populous of all sixty-four parishes. Tensas Parish was the home to many succeeding Native American groups in the thousands of years before European settlements began. Village and mound sites once built by these peoples have now become archaeological sites.
One example is the Flowery Mound, a rectangular platform mound just east of St. Joseph measuring 10 feet (3.0 m) in height and 165 feet (50 m) by 130 feet (40 m) at its base and a summit measuring 50 feet (15 m) square. Core samples taken during investigations at the site have revealed the mound was built in a single stage and because the fill types can still be differentiated it suggests the mound is relatively young. Radiocarbon dating of charcoal found in a midden under the mound reveals that the site was occupied from 996–1162 during the Coles Creek period.
The mound was built over the midden between 1200–1541 during the Plaquemine/Mississippian period. The corners are oriented in the cardinal directions. Several others include Balmoral Mounds, Ghost Site Mounds, and Sundown Mounds. During the American Civil War, private citizens, particularly planters, organized, equipped, and transported military companies. In Tensas Parish, cotton planter A.C. Watson provided one company of artillery with more than $40,000.
In April 1862, Governor Thomas Overton Moore, reconciled to the fall of New Orleans, ordered the destruction of all cotton in those areas in danger of occupation by Union forces. Along the levees and atop Indian mounds in Tensas Parish, thousands of bales of cotton burned for days. At the time, Tensas Parish was second only to Carroll Parish (subsequently divided into East and West Carroll) in the overall production of cotton in Louisiana.