Marion County is in northeastern Texas; its eastern boundary forms a portion of the Louisiana-Texas border. Jefferson, the county's largest town and its county seat, is seventeen miles north of Marshall, in Harrison County, and forty-six miles west of Shreveport, Louisiana. The county's center is at 32°47' north latitude and 94°20' west longitude. Marion County covers 380 square miles of the dense timberlands of East Texas. The land surface is a gently rolling, rich, sandy loam, underlain by a clay foundation and cloaked by pine, cypress, and oak forests. The elevation is 200 to 500 feet above sea level. The county is drained by the Red River basin via the watershed areas of Caddo Lake, Lake o' the Pines, and Big Cypress, Little Cypress, and Black Cypress bayous. The region's mineral deposits include oil, natural gas, clay, and lignite coal. Temperatures range from an average low of 32° F to an average high of 54° F in January and from 71° to 93° F in July. The growing season is 236 days in length, and the yearly rainfall is forty-four to forty-five inches. Marion County was demarked from the southern portion of Cass County by an act of the state legislature on February 8, 1860. Territorial additions in 1863 and 1874 extended its southern boundary to include both banks of Big Cypress Bayou. The county was named for American Revolutionary War hero Francis Marion, the "Swamp Fox."
Due to a large natural log-jam and collection of snags on the Red River, known as the Red River Raft, which formed a series of navigable lakes and bayous in the river valleys of Marion County, Jefferson, founded in the early 1840s, rapidly developed a booming river trade with New Orleans. Jefferson quickly became the favored inland Texas port for the deposit and transport of North Texas agricultural produce. Thus, Marion County became the commercial conduit for frontier Texas and did not relinquish this position until the establishment of transcontinental rail links that bypassed its wharves in the mid-1870s. Another important attribute of Marion County's early character was the geographical and cultural origins of its residents. Ninety percent of them migrated from the Deep South and the border states of Tennessee, Arkansas, and Missouri, bringing with them the slave economy of their former environment. In 1860 the slave population of Marion County constituted 51 percent of the total population. Slaveholders, though small in number (213), held 60 percent of the county's wealth and dominated its political institutions. Marion County sent two of its prominent citizens, James H. Rogers and William S. Todd, to the Secession Convention, and the county's voters unanimously approved the Ordinance of Secession in 1861.
The acquisition of lucrative Confederate government contracts proved to be a catalyst to the county's already growing economic fortunes. For example, the Kelly Iron Works, established in the antebellum period as a successful producer of agricultural implements, received a commission to manufacture cannonballs and rifles for the Confederate States Ordnance Department. J. B. Dunn's meat-packing firm was authorized to produce tinned beef for the Confederate commissary. Cut off from potential competition from eastern industrial firms and protected from invasion by its geographical location, Marion County's infant manufacturing sector and Jefferson's riverport commerce continued to expand and thrive throughout the Civil War.
The defeat of the Confederacy and the ensuing federal occupation led to the most volatile and tumultuous period in the county's political history. On October 4, 1869, George Washington Smith was murdered in Jefferson by a band of vigilantes. Smith's slaying led to the military occupation of Jefferson by Union troops under the command of Gen. George P. Buell, whose orders were to establish the security of citizens loyal to the United States and to arrest and try Smith's killers. The action taken by the military tribunal that followed was known as the Stockade Case. With military protection afforded the Black majority, the White Republican minority, through the use of the local Union League, took control of county government. Prominent among Marion County Republicans during the Reconstruction era were Donald Campbell, Colbert Caldwell, Charles Haughn, and A. G. Malloy. Republicans continued to serve in county political offices through the decade of the 1870s. The restoration of White conservative rule, commonly called "redemption," did not come until 1882 with the election of a Democrat-dominated commissioners' court. However, despite violence and intimidation aimed at the Black majority throughout the remainder of the nineteenth century, Blacks continued to deliver Marion County's majority for the Republican presidential ticket until the white primary effectively disfranchised them in 1898. From this point on, county voters returned a majority for Democratic presidential candidates in every election through 1996 except in 1956 when Republican Dwight Eisenhower carried the area, and 1984, when Ronald Reagan did. Republican George W. Bush carried the county with comfortable majorities in 2000 and 2004.
In spite of the intense passions engendered by Reconstruction politics, the county's prominent citizens were able to separate politics and financial necessity, opposing a proposed boycott of Republican businesses in 1869 and 1870. Few disliked the Republicans enough to refuse to do business with them. The 1870 census ranked Jefferson second in commerce and industry among all Texas cities. Such modern novelties as gas lighting, artificial ice, refrigeration, and soda water were in common use by Jefferson's commercial elite. Cotton exports from Jefferson's wharves increased from 25,000 bales in 1865 to 76,238 bales in 1872. However, material wealth and commercial optimism plummeted during the mid-1870s. Jefferson's unchallenged monopoly over the trade of approximately twenty northern Texas counties was broken by the construction of two east-west rail routes during the 1870s, linking the Grand Prairie farmlands directly with eastern markets. At this point, the flight of capital and skilled labor from Marion County began in earnest. Between 1870 and 1880 the county lost 138 businesses and began to resemble more nearly the other rural counties contiguous to it. In 1870 urban residents made up 50 percent of the county's population, but by 1900 they constituted only 26 percent. During the 1870s and 1880s the number of farms in the county grew rapidly, from 186 to 1,063, as many of the large plantations were broken up and sold or turned over to share croppers. Cotton and corn constituted the leading crops, with cattle, swine, and other livestock contributing to the farm income.
The discovery of oil in 1910 and the subsequent speculation and production that followed resulted in an expansion of the county's nonagricultural economy for the first time since the 1870s. By 1920 Marion County had acquired sixty new businesses, including eleven manufacturing firms. Between 1923 and 1928 the number of motor vehicles in the county rose from 541 to 1,222. Agricultural production also grew, producing a record 9,638 bales of cotton and 57,000 bushels of corn in 1926. However, by 1945 row-crop agriculture was negligible; it produced no cotton and little truck-farm produce for the marketplace.
The Great Depression of the 1930s dealt an initially severe blow to the economy, wiping out 70 percent of the county's manufacturing and 32 percent of all businesses and forcing 828 workers onto the relief rolls. Automobile ownership, a symbol of modern prosperity and success, plunged 20 percent by 1933. However, the combination of an improving oil market, the large public works projects taking place at the newly established Caddo Lake State Park in neighboring Harrison County (1933–37), and other federal subsidies by agencies such as the Civilian Conservation Corps led Marion County to a remarkable recovery. By 1941 the number of businesses had increased 87 percent, and two new manufacturing firms had opened. Motor vehicle registration jumped 41 percent during the same year. The county's population rose 12 percent between 1930 and 1940. Data for 1940 show a 70 percent decrease in unemployment between 1935 and 1940.
The next three decades witnessed a 25 percent decline in Marion County's population and the demise of over 80 percent of the farms. Of the 223 remaining farms in 1970, 205 were devoted solely to cattle, and only sixty-five of these sold more than $2,500 worth of stock. The economy expanded in manufacturing establishments, from seven in 1940 to twenty-six in 1970. However, the vast majority of these employed fewer than ten people. Marion County did not experience economic growth again until the decade of the 1970s. The prosperity experienced throughout the 1970s was due to a substantial rise of tourism, stimulated by the reconstructed and renovated Jefferson Historic Riverfront District and the recreation opportunities offered by Caddo Lake State Park and Lake o' the Pines. This influx of tourism caused a boom in the service and retail sectors. By 1983, 67 percent of all employment was in this retail and service sector, up 12 percent over the 1964 figure. Though small manufacturing establishments remained important to the economic health of the county, their share of earnings remained static during the same period. Agriculture and timbering rose slightly during the decade. Events like the annual Pilgrimage Celebration, a three-day open-house tour of some of Jefferson's more than ninety state-designated historical monuments, homes, hotels, and a museum came to account for hundreds of thousands of tourist dollars a year in the local economy. As a result of the county's new attractiveness for investment, its taxable income total rose 79 percent between 1976 and 1984. In motor vehicle registration alone, Marion County posted a 182 percent increase between 1970 and 1980. Demographic and social shifts in the population also marked the county's character in the 1970s. In 1970 the racial balance tipped toward the White population for the first time since the county's founding in 1860. By 1980, 65 percent of the county's population was White. In 1990 the population of Marion County was 9,984.
In 2014 the census counted 10,149 people living in Marion County. About 71 percent were Anglo, 22 percent were African American, and 3.8 percent were Hispanic . Almost 68 percent of residents age twenty-five and older had four years of college, and almost 6 percent had college degrees. In the early twenty-first century tourism, timber, and food processing plants were key elements of the area’s economy. In 2002 the county had 252 farms and ranches covering 59,602 acres, 38 percent of which were devoted to woodlands, 35 percent to pasture, and 29 percent to crops. In that year farmers and ranchers in the area earned $4,087,000, with livestock sales accounting for $3,343,000 of the total. Beef cattle, hay, and goats were the chief agricultural products. More than 11,652,000 cubic feet of pinewood and almost 1,805,000 cubic feet of hardwood were harvested in the county in 2003, and more than 181,000 barrels of oil and 4,735,632 cubic feet of gas-well gas were produced there in 2004. By the end of that year 55,597,674 barrels of oil had been taken from county lands since 1910. Jefferson (population, 2,011) is the county’s seat of government and largest town. Other communities include Berea, Gethsemane Community, Gray, Hartzo, Jackson, Kellyville, Lassater, Lodi, Lodwich, Orrs, Potters Point, Prospect, Smithland, Sunview, and Warlock.