Question: Who was the first non-colonial governor of Louisiana and the brother of Nathaniel Claiborne?
Context: This is a list of Missouri Confederate Civil War units, or military units from the state of Missouri which fought for the Confederacy in the American Civil War.  A border state with both southern and northern influences, Missouri attempted to remain neutral when the war began.  However, this was unacceptable to the Federal government, and Union military forces moved against the capital to arrest the legislature and the governor.  Governor Claiborne Jackson called out the Missouri State Guard to resist.  Union forces under Gen. Nathaniel Lyon seized the state capital, and a minority of pro-Union members of the legislature declared the governor removed from office.  They appointed a pro-Union governor, and the Federal government recognized him even though he had not been elected.  This resulted in a civil war within the state, as Missourians divided and joined both the Union and Confederate armies.  Missouri sent representatives to the United States Congress and the Confederate States Congress, and was represented by a star on both flags. Nathaniel Herbert Claiborne (November 14, 1777 – August 15, 1859) was a nineteenth-century politician from Virginia.  He was the brother of William Charles Cole Claiborne, the nephew of Thomas Claiborne, the uncle of John Francis Hamtramck Claiborne and the great-great-great granduncle of Marie Corinne Morrison Claiborne Boggs and Claiborne de Borda Pell.  He was a descendant of Colonel William Claiborne (1600–1677), who was born in Crayford, Kent, England and settled in the Colony of Virginia. Elysian Fields Avenue is a broad, straight avenue in New Orleans named after the Avenue des Champs-Élysées in Paris.  It courses south to north from the Lower Mississippi River to Lake Pontchartrain, a distance of approximately 5 mi .  The avenue intersects with Interstate 610, Interstate 10, and U.S. Highway 90, Gentilly Boulevard passing by Brother Martin High School.  The part between North Claiborne Avenue (Louisiana Highway 39) and Gentilly Boulevard (U.S. Route 90) is Louisiana Highway 3021 (LA 3021); the piece from N. Claiborne Avenue south to St. Claude Avenue carries Louisiana Highway 46 (which turns east on St. Claude Avenue). John Sidney Garrett (October 29, 1921 – May 28, 2005) was a conservative Democratic member of the Louisiana House of Representatives who served from 1948 to 1972 under four gubernatorial administrations.  Garrett was a successful businessman in the small town of Haynesville in Claiborne Parish south of the Arkansas state line.  In his last term, he was defeated for reelection even though he was the Speaker of the House.  In 1966, Garrett made a strong but losing primary race for the Louisiana Public Service Commission to fill the seat vacated by the election of John McKeithen as governor.  At the time, there were only three PSC districts; the number was increased to five under the Louisiana Constitution of 1974. Claiborne Parish (French: "Paroisse de Claiborne" ) is a parish located in the northwestern section of the U.S. state of Louisiana.  The parish was formed in 1828, and was named for the first Louisiana governor, William C. C. Claiborne.  As of the 2010 census, the population was 17,195.  The parish seat is Homer. John Sidney Killen (February 5, 1826 – December 28, 1903) was a pioneer farmer and cattleman from Claiborne and Webster parishes in northwestern Louisiana, who served in the Louisiana House of Representatives for Claiborne Parish in 1871 during the term of the Reconstruction Governor Henry Clay Warmoth. Antoine Jacques Philippe de Marigny de Mandeville (1811–1890), (also known as Antoine James de Marigny and Mandeville de Marigny), was the son of Bernard de Marigny de Mandeville and Anna Mathilde Morales, and the son-in-law of William C. C. Claiborne, the first Governor of Louisiana after statehood.  He was a planter, merchant, military officer, and U.S. Marshal for eastern Louisiana. Dorothy Garrett Smith (c. 1932 – August 8, 1990) was the first woman to have served as president of the Louisiana Board of Elementary and Secondary Education, which establishes and monitors education policy.  Smith was the president from December 1989 until her sudden death eight months later during the administration of Governor Buddy Roemer.  She represented nine parishes in northwestern Louisiana: Beauregard, Bossier, Caddo, Claiborne, DeSoto, Red River, Sabine, Vernon, and her own Webster. Richard Maxwell Drew (June 26, 1822 – July 11, 1850) was an attorney and politician in Claiborne Parish in North Louisiana.  His family was among the first settlers of what is now Webster Parish, established in 1871 as a breakaway from Claiborne Parish. William Charles Cole Claiborne (c.1773-75 – 23 November 1817) was a United States politician, best known as the first non-colonial Governor of Louisiana.  He also has the distinction of possibly being the youngest Congressman in U.S. history, though reliable sources differ about his age.
Answer: William Charles Cole Claiborne