Marengo County is a county of the U.S. state of Alabama. As of the 2010 census, the population was 21,027. The largest city is Demopolis and the county seat is Linden. It is named in honor of a battlefield near Turin, Italy, where the French defeated the Austrians on June 14, 1800.
Marengo County was created by the Alabama Territorial legislature on February 6, 1818, from land acquired from the Choctaw Indians by the Treaty of Fort St. Stephens on October 24, 1816. The name of the county commemorates Napoleon's victory at the Battle of Marengo over the Austrian armies on June 14, 1800. This name was chosen as a compliment to the first Caucasian settlers, exiled French Bonapartists who in 1817 settled the area around Demopolis in an effort to establish a Vine and Olive Colony. The county seat was originally known as the Town of Marengo, but in 1823 the name was changed to Linden. Linden is a shortened version of Hohenlinden, scene of another Napoleonic victory in Bavaria in 1800.
Situated in Alabama's Black Belt and having a naturally rich soil, the county became home to numerous cotton plantations and consequently a large number of slaves. In 1860 the population consisted of 24,409 slaves, 6761 free whites including 944 slave owners, and just 1 "free person of color" for a total combined population of 31,171. At this time there were 778 farms in the county. Demopolis was home to the fourth oldest Jewish congregation in Alabama, B'nai Jeshurun. It was established in 1858. After the American Civil War, the economy continued to be based on agriculture with the former plantations turning to sharecropping.
The population began to diminish rapidly after World War II, with people leaving the farms for manufacturing jobs elsewhere. The former cotton fields were gradually converted to pastures for cattle and horses, woodlands for timber, and commercial catfish ponds for grain fed catfish. Beginning in the 1960s industry began to move into the area and the working force came to be employed by paper mills, lumber mills, and chemical plants. Courthouse fires occurred in 1848 and 1965, but most of the courthouse records were in a vault and thus largely saved in both instances.