 Rather than stay in Australia Frost immediately left for the United States, with his daughter, Catherine, who had joined him in Tasmania, and toured the country, organised by William Prowting Roberts, lecturing on the unfairness of the British system of government.In 1856, when the residency condition was lifted, Frost was given an unconditional pardon and he straightaway sailed for Bristol.He retired to Stapleton, near the city, but continued to publish articles advocating reform until his death there, aged 93, in 1877.