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 in height and 165 feet by 130 feet at its base and a summit measuring 50 feet 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.

Near Newellton is the Winter Quarters Plantation restoration, where Union General Ulysses S. Grant and his men spent the winter of 1862-1863, prior to launching the assault in the spring and summer of 1863 against Vicksburg, Mississippi, to the northeast of Tensas Parish.

In 1864, Captain Joseph C. Lea of the Missouri guerrillas, with two hundred men, moved into Tensas Parish and came upon a fortification held by four hundred Federal soldiers under the command of Colonel Alfred W. Eller. Lea inflicted heavy casualties and drove the men to the Mississippi River, where they boarded their boats. Lea seized a federal warehouse with gunpowder, groceries, and medical supplies. Facing attacks from the Union forces who tried to return to their fortification, Lea managed to secure seventy-five Federal wagons and cotton carts, all of which he dispatched to Shreveport.

Franklin Plantation, owned by a physician, Allen T. Bowie, was considered the most elegant of the antebellum homes about the oxbow lake, Lake St. Joseph, near Newellton. A Missouri Confederate wrote that the area was "unsurpassed in beauty and richness by any of the same extent . . . in the world." Union officers in charge of the XIII and XVII Corps kept close watch on the troops to prevent looting as the men marched southward headed indirectly to Vicksburg. When General William Tecumseh Sherman's XV Corps joined Grant's forces, however, the soldiers became lawless. On May 6, 1863, rowdies from General James Madison Tuttle's division burned most of the mansions which fronted Lake St. Joseph, including Dr. Bowie's beloved Franklin Plantation.

Toward the end of the war, schools were established for African American children in northeastern Louisiana, including Tensas and Concordia parishes, some through the sponsorship of the American Missionary Association. According to the historian John D. Winters of Louisiana Tech University, the students "ranged in age from four to forty, were poorly clothed, loved to fight, and were 'extremely filthy, their hair filled with vermin.' Religious instruction, with readings from the Bible and prayers, was emphasizsed while reading from primers and studying spelling and writing rounded out the course work. The program stressed 'a maximum of memory and a minimum of reasoning.' The schools sponsored by the Christians societies were gradually taken over by a board of education and supported by special property and crop taxes. These schools operated primarily along the Mississippi and few, if any, were established in the interior [of Louisiana]."

By the turn of the 20th century, with Civil War memories still present in the people's minds, St. Joseph numbered no more than 720 residents (and Tensas Parish, 19,070), most having been engaged in cotton growing and related river work.

The parish has a total area of 641 square miles, of which 602 square miles is land and 39 square miles (6.04%) is water. The population recorded in the 1850 Federal Census was 9,040. The 2010 census recorded 5,252 residents in the Parish.

Neigboring parishes and counties are Warren County, MS (northeast), Claiborne County, MS (east), Jefferson County, MS (east), Adams County, MS (southeast), Concordia Parish (south), Catahoula Parish (southwest), and Franklin Parish (west). Communities in the parish include Newellton, St. Joseph, and Waterproof.

Birth Records - The Louisiana State office maintains records for 100 years after the date of birth. Birth records are considered confidential for the first 100 years. For current information on who may obtain a birth record as well as how to submit a request visit the Office of Public Health, Vital Records Registry website or write to them at PO Box 60630, New Orleans, LA 70160.

Birth records older than 100 years are available through the Louisiana State Archives, 3851 Essen Lane, Baton Rouge, LA 70809. (225) 922-1000.

Death Records - The Louisiana State office maintains records for 100 years after the date of death. Death records are considered confidential for the first 100 years. For current information on who may obtain a death record as well as how to submit a request visit the Office of Public Health, Vital Records Registry website or write to them at PO Box 60630, New Orleans, LA 70160.

Death records older than 100 years are available through the Louisiana State Archives, 3851 Essen Lane, Baton Rouge, LA 70809. (225) 922-1000.

Marriage Records - For current information on how to submit a request for a certified copy of an Orleans Parish marriage record less than 50 years old, see the Louisiana Office of Public Health Director, Vital Records and Statistics website or write to PO Box 60630, New Orleans, LA 70160.

Certified copies for the parish are issued by Clerk of Court. For the address of the parish Clerk of Court visit the Tensas Parish Important Addresses page.

Marriage records over 50 years are stored by the Louisiana State Archives, 3851 Essen Lane, Baton Rouge, LA 70809. (225) 922-1000.

Divorce Records - To obtain current information on how to submit a request for a certified copy of divorce records contact the Clerk of Court. For the address of the parish Clerk of Court visit the Tensas Parish Important Addresses page.