The history of the Underground Railroad is one of individual sacrifice and heroism of enslaved people to achieve freedom from bondage. Perhaps the most dramatic protest against slavery in the United States, it was an operation that began during the colonial period and later became part of the organized abolitionist activity in the 19th century and reached its peak in the period 1830-1865. While most runaways began their journey unaided, many completed their self-emancipation without assistance. Each decade during slavery in the United States, there was an increase in the public perception of an underground network and in the number of persons willing to give aid to the runaways.