In 1849, Brown left the United States with his two young daughters to travel in the British Isles to lecture against slavery. He wanted them to gain the education he had been denied. He was also traveling that year as a representative of the US at the International Peace Congress in Paris. Given passage of the Fugitive Slave Act of 1850 in the US, which increased penalties and more severely enforced capture of fugitive slaves, he chose to stay in England until 1854. That year his freedom was purchased by British friends. As a highly visible public figure in the US, he was at risk for capture as a fugitive and re-enslavement. Slave catchers were paid high bounties to return slaves to their owners, and the new law required enforcement even by free states and their citizens, although many resisted.