The Underground Railroad was a secret network of routes and safe houses used by black slaves in the United States to escape to free states and Canada with the help of abolitionists and those who had sympathy to their cause. The term is also applied to the abolitionists, both black and white, free and enslaved, who helped the slaves. Other various routes led to Mexico or overseas. Created in the early 1800s, the Underground Railroad was at its biggest between 1850 and 1860. One statistic suggests that by 1850, 100,000 slaves had escaped by the "Railroad". British North America, where slavery was not allowed, was a popular stopping point, as its long border gave many points of access. More than 30,000 people were said to have escaped there using the network at its best, although U.S. Census statistics shows only 6,000. The Underground Railroad fugitives' stories are recorded in the Underground Railroad Records.