The Underground refers to a network of secret routes and safe houses used by enslaved people in the United States during the 19th century. This system helped them escape to free states and Canada, where slavery was illegal. Abolitionists and sympathetic individuals, known as "conductors," played a crucial role in guiding and supporting these escapees. The term is also associated with the Underground Railroad, a metaphorical name for this movement. It was not an actual railroad but rather a series of paths and safe havens. Many brave individuals risked their lives to assist those seeking freedom, making it a significant part of American history.