Why was the Fugitive Slave Act the most controversial legislation produced by the Compromise of 1850?
America had different lifestyles especially because of the natural resources availability. Although agriculture had dominated the economy, its importance varied by region. Southern economy was dominated by farming, where evolved slavery, as most farmers required them for carrying out their works. Northern States were deprived of fertile soil, and there developed a mercantile economy which had a stark difference from that of the south.
Many Southerners wanted to safeguards their lifestyle as they felt threatened by the urban culture that had evolved in the North. One such safeguard was constitutional and legal provisions that directed the return of escapee slaves to their legal owners.
Article IV, section 2 of the Constitution, directed that "no person held to service or labor in one state, under the laws thereof, escaping into another, shall, in consequence of any laws or regulation therein, be discharged from such service or labor, but shall be delivered up, on claim of the party to whom such service or labor may be due." The Congress later enacted the Fugitive Slave Act of 1793 which laid down the procedure for the recovery of runaway slaves.
As discussed earlier slavery was prevalent in the South, whereas in north anti-slavery sentiment was quite strong. So the slaveholders in the south faced immense difficulty in recovery of runaway slaves because of the personal liberty laws that were enacted by most northern states. One such law even forbade state officials from participating in the attempt to get back fugitive slaves.
The challenges / problem / question of runaway slaves was yet again placed in front of the Congress in the Compromise of 1850, resulting in the enactment of the Fugitive State Law considered to be the most controversial decision of the compromise. The law contained provisions strengthening the rights of slaveholders in their pursuit of runaway slaves. It allowed any Federal marshal or other official not arresting an alleged runaway slave liable to a fine of $1,000. In the whole of America any Law-enforcement officials had the duty of arresting anyone who was suspected of being a runaway slave just on the basis of the claimant's sworn testimony of ownership. The suspected slave could not even ask for a trial or testify on his/her own behalf. Additionally, any person found to have aided a runaway slave either by providing food or by providing shelter was liable for imprisonment for a period extending six months and a fine of $1,000. Officers who captured a fugitive slave were given bonus. Slave owners just required to file an affidavit to a Federal marshal to capture an escaped slave. This act resulted in many free blacks conscripted into slavery as a suspected slave was neither eligible for a trial nor could not defend himself against accusations.
This lead to rampant slavery especially in the south as it benefitted both the slaveholders as well as the field marshal as he would be rewarded from both the parties; the government and the slaveholders. But this act was against human rights as anyone could be made a slave, especially gave rise to racism as mostly blacks were the ones who got caught in this whole process.
This act raised a huge protest in the north which passed even stronger personal liberty laws and made Canada the place for the runaway slaves, as slaves from south would run to north to save themselves from the states laws and people in the north to save them from the union law used to get them across the border to Canada. A lot of opposition was raised in the northern and southern, newspapers. Even a novel Uncle Tom's Cabin was published in 1852; it was encouraging the public against slavery.
Also this compromise could be stated as one of the major causes that lead to the American Civil War in which started in 1861 where eleven southern states broke away the United States and formed the Confederate States of America.