Duke Friedrich Paul Wilhelm of Württemberg (; 25 June 1797, in Bad Carlsruhe, Silesia, Kingdom of Prussia – 25 November 1860, in Mergentheim, Kingdom of Württemberg) was a member of the House of Württemberg and a Duke of Württemberg. Paul Wilhelm was a German naturalist and explorer, who in the early 19th century, undertook several expeditions in North America, North Africa, and Australia. In 1829, he discovered the sources of the Missouri River. Family Paul Wilhelm was the fifth and youngest child of Duke Eugen of Württemberg and his wife Princess Luise of Stolberg-Gedern. Through his father, Paul Wilhelm was a grandson of Frederick II Eugene, Duke of Württemberg and his wife Friederike Dorothea of Brandenburg-Schwedt. He was a nephew of Frederick of Württemberg, the first King of Württemberg. Expeditions Between the years 1822 to 1824, Paul Wilhelm undertook his first major research trip to Cuba and North America. He kept a diary in which he described the places he visited in great scientific and ethnological detail. An artist produced numerous images of the landscapes, plants, and animals. Paul Wilhelm devoted himself particularly to the study of North and South America. He spent time exploring the western United States and met the son of Sacagawea, Jean Baptiste Charbonneau. After his initial meeting with Jean Baptiste Charbonneau in 1823 at the Kansas River, likely arranged by William Clark, Paul Wilhelm left camp and headed north with Great Plains veteran Toussaint Charbonneau, Jean Baptiste's father and Sacagawea's husband, hired as an interpreter. The Duke’s party spent five months in the upper Missouri country visiting trading forts, Indian tribes, and collecting scientific data. Paul Wilhelm is traditionally included as one of the first explorers of the headwaters of the Mississippi and Missouri rivers. As late as the 1850s, he visited Baron Ottomar von Behr, a German farmer and sheep breeder, meteorologist, and scientist living in Sisterdale, Texas. When he visited New Braunfels on an 1855 visit, artist Carl G. von Iwonski made him a gift of six pencil sketches of the artist's Texas work. Marriage and later life Paul Wilhelm married his second cousin Princess Maria Sophia of Thurn and Taxis, fifth child and fourth daughter of Karl Alexander, 5th Prince of Thurn and Taxis and his wife Duchess Therese of Mecklenburg-Strelitz, on 17 April 1827 in Regensburg. Paul Wilhelm and Maria Sophia Dorothea had one son: Duke Wilhelm Ferdinand Maximilian Karl of