In his home in Scotland Brown had been imbued with a hatred of slavery. He spent several years of his early manhood in New York, and felt in all its force the domination of the slave-holding element. Thence he moved to Canada, for many years the refuge of the hunted slave. It is estimated that even before the passage of the Fugitive Slave Law, there were twenty thousand coloured refugees in Canada. It was customary for these poor creatures to hide by day and to travel by night. When all other signs failed they kept their eyes fixed on the North Star, whose light "seemed the enduring witness of the divine interest in their deliverance." By the system known as the "underground railway," the fugitive was passed from one friendly house to another. A code of signals was used by those engaged in the work of mercy--pass words, peculiar knocks and raps, a call like that of the owl. Negroes in transit were described as "fleeces of wool," and "volumes of the irrepressible conflict bound in black." The passage of the Fugitive Slave Law deprived the negro of his security in the free states, and dragged back into slavery men and women who had for years been living in freedom, and had found means to earn their bread and to build up little homes. Hence an impetus was given to the movement towards Canada, which the slave-holders tried to check by talking freely of the rigours of the Canadian climate. Lewis Clark, the original of George Harris in _Uncle Tom's Cabin_ was told that if he went to Canada the British would put his eyes out, and keep him in a mine for life. Another was told that the Detroit River was three thousand miles wide. But the exodus to Canada went on, and the hearts of the people were moved to compassion by the arrival of ragged and foot-sore wanderers. They found a warm friend in Brown, who paid the hotel bill of one for a week, gave fifty dollars to maintain a negro family, and besides numerous acts of personal kindness, filled the columns of the _Globe_ with appeals on behalf of the fugitives. Early in 1851 the Anti-Slavery Society of Canada was organized. The president was the Rev. Dr. Willis, afterwards principal of Knox Presbyterian College, and the names of Peter Brown, George Brown, and Oliver Mowat are found on the committee. The object of the society was "the extinction of slavery all over the world by means exclusively lawful and peaceable, moral and religious, such as the diffusion of useful information and argument by tracts, newspapers, lectures, and correspondence, and by manifesting sympathy with the houseless and homeless victims of slavery flying to our soil." Concerts were given, and the proceeds applied in aid of the refugees.