The Fugitive Slave Act was perhaps the most detested law in all American history.
A product of the Compromise of 1850, which brought California into the union as a non-slave state, the act allowed slaveowners, or even purported slaveowners, to pursue escaped slaves across state lines, made harboring a fugitive a criminal act and required local officials to assist the pursuers.
"It was an act without mercy," wrote historian Andrew Delbanco in his 2018 book about pre-Civil War America, "The War Before the War."
