The qualms about the Caribbean (and about New Orleans) fed qualms about the illegality of filibustering. Before U.S. filibusterers could replace foreign regimes, they had to defy their own national’s Neutrality Laws. Back when the new American government had striven to be neutral in Europe’s Napoleonic Wars, Congress had passed these laws. These edicts required private individuals to be as neutral as their government. American citizens could not join foreign wars, civil conflicts, or revolutions when the United States remained at peace with the combatants. .

The ranks of free people of color were constantly increased by ex-slaves. Some, like Fredrick Douglass and Harriet Tubman, were fugitives. Douglass had paid his owner $3 a month for the privilege of hiring himself out as a ship caulker in Baltimore. Living among free workers gave him an opportunity to escape slavery. By masquerading as a free black with the help of borrowed seaman’s papers, he bluffed his way to Philadelphia and freedom. Tubman, a slave in Maryland, escaped to Philadelphia in 1849 when it was rumored that she would be sold out of the state.

The Fugitive Slave Act of 1850 caused fear and alarm among many Northerners. In response to the measure, some African Americans, hiding in northern cities, fled to Canada, often with the aid of conductors on the Underground Railroad. Abolitionists, white and black, made dramatic rescue attempts on behalf of men and women sought by their self-proclaimed southern owners. In Boston in 1851, a waiter named Shadrach Minkins was seized at work and charged with running away from a Virginia slaveholder.

Abolitionists clamored for the immediate emancipation of all slaves. Black men and women worked with abolitionists in the upper South and the North to help slaves escape through a network of safe stops called the Underground Railroad. The “railroad” consisted of Northerners, white and black, who sheltered fugitives from southern slavery in their flight to the North or, in some instances, to Canada.

Slaves constantly protested their bondage, both through group and individual actions. Several small uprisings took place in the early 1800s. Then, in 1831 Nat Turner organized a violent revolt in Virginia. Turner and his followers killed some 60 whites before being captured. These uprisings led southern states to pass stricter slave codes that further limited slaves’ activities.

As time went on, free African Americans and white abolitionists developed a secret network of people who would, at great risk to themselves, aid fugitive slaves in their escape. This network became known as the Underground Railroad. The “conductors” hid fugitives in secret tunnels and false cupboards, provided them with food and clothing and escorted or directed them to the next “station,” often in disguise.

The Underground Railroad wasn’t a real railroad with tracks and trains. It was a network of people and routes – on land and water – that helped slaves escape from the South in the mid-1800s.

Thousands of people in cities, villages, and farm areas of the United States, Canada, and Mexico were part of the network.

Between 30,000 and 100,000 slaves escaped to freedom on the “Railroad” between the 1830s and the end of the Civil War.

In 1793, a federal law gave muscle to the provision by authorizing slave owners to enter other states to recapture their slave property. Proclaiming the 173 law a license to kidnap free blacks, northern states in the 1830s began passing "personal liberty laws" that provided fugitives with some protection.

Clay's compromise plan, proposed in February 1850, took several months to get through Congress. One obstacle was President Taylor's firm resistance to the proposal; another was the difficulty of getting congressmen to vote for it in the form of a single package or "omnibus bill." Few politicians from either section were willing to go on record as supporting the key concessions to the other section.

John C. Calhoun warned that agitation over slavery and the North's actoion would snap "the cords which bind these states together…nothing will be left to hold the states together except force." He would rather see the South secede from the Union, and prayed that the separation would be peaceful.