In the 19th century, numerous expeditions were launched to explore uncharted territories and expand scientific knowledge. Notable expeditions included those led by Lewis and Clark in the early 1800s, which mapped the western United States, and Charles Darwin's voyage on the HMS Beagle, which contributed to the development of the theory of evolution. These expeditions often involved significant challenges, including harsh weather, difficult terrain, and interactions with indigenous peoples. They played a crucial role in advancing geography, biology, and anthropology, while also paving the way for future exploration and colonization efforts around the world.