Prince Maximilian Alexander Philipp of Wied-Neuwied was a German explorer and naturalist who traveled through the United States in 1832–34. He became well known for his studies of the Northern Plains Indians, especially the Mandans and Hidatsas.

Prince Maximilian was born the eighth of eleven children on September 23, 1782, in the city of Neuwied, Germany. His parents were Friedrich Carl Count of Wied-Neuwied (1741–1809) and Louise Wilhelmine Countess of Sayn-Wittgenstein-Berleburg (1747–1823). The most influential people in Maximilian's career were Johann Friedrich Blumenbach, the Enlightenment's leading theorist on comparative anthropology, and naturalist Alexander von Humboldt, who became his mentor and friend after they met in Paris in 1814.

Whenever Prince Maximilian was free of military service in the Prussian army, he diligently pursued his scientific studies. He learned his skills as a naturalist mainly on his own, but he also enrolled at the University of Göttingen in 1811–12 to study under Blumenbach. In 1815, encouraged by Humboldt, Maximilian led his first major expedition to Brazil, where he studied the flora and fauna of the Mata Atlantica and Indigenous peoples such as the Botocudo, Purí, and Pataxo. Upon returning to Germany in 1817, Maximilian devoted himself to the analysis of his Brazilian experience, which culminated in the two-volume 1815–17 (1820–21).

In the late 1820s Maximilian began preparations for a second major expedition. Originally he played with the idea of exploring Labrador or the Kirgisian Steppe in Russia, but by 1830 he had decided to travel to North America. One stated purpose of this journey was to continue his investigation of the flora and fauna of the Americas, but he also intended to study the Indigenous cultures of North America and compare them with those of southeastern Brazil. In May of 1832 Maximilian, accompanied by the Swiss painter Karl Bodmer, left Europe for the United States, where they arrived in early July. After a tour of eastern cities they traveled west. Because of a serious illness resembling cholera, Maximilian was forced to stay the winter of 1832–33 in New Harmony, Indiana, where he enjoyed the company of fellow naturalists Thomas Say and Charles Alexandre Lesueur.

In the spring of 1833 Maximilian finally arrived in St. Louis, where he made arrangements to travel up the Missouri with boats belonging to the American Fur Company. After short stops at Forts Pierre, Clark, and Union, Maximilian arrived at Fort McKenzie, the westernmost point of his expedition, in August of 1833. Originally Maximilian wanted to extend his studies farther upriver into the Rocky Mountains, but the hostility of the three Blackfeet tribes forced him to reconsider this plan. After about five weeks of fieldwork around Fort McKenzie, Maximilian returned to Fort Clark to stay for the winter of 1833–34. There he devoted his time to a thorough study of the Mandans and Hidatsas and to a less complete analysis of the nearby Arikaras.

In his travel accounts Maximilian routinely described the physical appearance of the Indigenous peoples he encountered, then concentrated on recording their customs, languages, and cultures, including one of the most important ceremonies of the Mandans, the Okipa. Maximilian's visit to the upper Missouri came at a time when the fur trade was altering the social, political, and cultural characteristics of the Northern Plains tribes, and he recorded many of these changes, even though he was not always aware of their significance. His travel writings also reinforced the Romantic interest in the "noble savage," an invented image that had fascinated intellectuals throughout Europe since the late Renaissance.

In April of 1834 the Prince journeyed back to the East Coast, then on to Europe in July. As soon as he returned to Neuwied, Maximilian began the synthesis of his expedition, which culminated in the publication of the two-volume (1839–41). In the years following, and until a few years before his death on February 3, 1867 in Neuwied, he continued to publish articles on his North American experience. Maximilian's legacy survives in the nomenclature of Plains plants and animals (for example, the sunflower Helianthus maximilianii and the Cretaceous saurian Mosasaurus maximiliani).

See also ART: Bodmer, Karl / INDUSTRY: American Fur Company / RELIGION: Okipa.