## The Fugitive Slave Act and the Decision to Leave
On September 18, 1850, President Millard Fillmore signed the Fugitive Slave Act. The law was the most aggressive federal enforcement mechanism for slavery that had yet existed. It required citizens in free states to assist in the capture of freedom seekers. It denied accused freedom seekers the right to testify on their own behalf. It imposed penalties on those who aided or harbored them. It offered financial incentives to commissioners who ruled in favor of enslavers.
For Henry Box Brown, still in the United States, the Fugitive Slave Act was not an abstract political development. It was a direct and personal threat. He was a known freedom seeker, widely publicized, whose former enslaver — or the enslaver’s representatives — could now pursue him with the full backing of federal law into any state he was in.
Brown was assaulted in Providence, Rhode Island, on August 30, 1850 — before the Act was signed, but as it was clearly about to become law. The assault is documented in contemporary accounts. It was the kind of violence that the looming legal change encouraged: a freedom seeker visible enough to be found, in a city where the law was about to become actively hostile to him.
In October 1850, Henry Box Brown and James C. A. Smith sailed for England.
## Britain and a Second Act
They arrived in Liverpool in October 1850. The Mirror of Slavery opened there on November 12 and ran through early December before moving to Manchester and then through Lancashire and Yorkshire. The antislavery movement in Britain was substantial — the country had abolished slavery in its colonies in 1833, and British audiences were receptive to American abolitionist speakers in ways that included both genuine moral concern and a kind of moral self-congratulation about British precedence. Brown was not unaware of this dynamic, and his performances in Britain were calibrated for British audiences.