Estimates suggest that approximately 100,000 to 150,000 slaves managed to escape during this period. The vast majority of these escapes occurred after 1850, following the passage of the Fugitive Slave Act, which further heightened tensions between the North and the South and led to an increase in both the motivation and assistance for slaves to flee to freedom.
It's important to note that these estimates may vary depending on the criteria used to define an "escape." Some sources include only those slaves who successfully reached free states or territories, while others also count slaves who were apprehended and returned to slavery or who died during their attempts to escape.
Nonetheless, it is widely acknowledged that the number of slaves who escaped to freedom during the 1830s and 1840s played a significant role in the broader struggle against slavery and contributed to the growing momentum towards the abolitionist movement.