After intensive police investigation, Davitt was arrested at Paddington Station in London on 14 May 1870, while awaiting a delivery of arms. Tried at Old Bailey in July, Davitt was convicted of treason felony for arms trafficking in support of insurrection and sentenced to fifteen years of penal servitude. He believed that he had had neither fair hearing nor adequate defence counsel. Imprisoned at Millbank, Dartmoor, and Portsmouth, Davitt was held for months in solitary confinement and endured hard labour and poor rations that permanently damaged his health. However, he frequently broke the prison rules and his main objection was that he was treated the same as criminals even though he considered himself a political prisoner. In 1872, he smuggled a letter out of the prison which was published in several newspapers and led to an inquiry by the Home Secretary into his allegations. Davitt was paroled on 19 December 1877, having served seven and a half years, following pressure from the Home Rule League for an amnesty for all Irish political prisoners. He and other freed prisoners were welcomed by Isaac Butt and the Political Prisoners Visiting Committee in London and returned to a "heroes' welcome" in Ireland. Davitt published a book about his prison experience, and began a campaign for the release of remaining Fenian prisoners. His popularity caused him to try his hand at writing and lecturing, which he discovered he had a talent for. He also rejoined the IRB, and became a member of its Supreme Council representing Northern England. Nevertheless, the success of the amnesty movement led him to appreciate the value of political, rather than physical force, approaches to achieving Irish republican goals. His experiences in prison made him a lifetime supporter of prison reform for humane conditions for all prisoners. This was in contrast to other Irish nationalists who had served prison time, who were only interested in the condition of "political" prisoners. Shortly before his arrest, Davitt had persuaded his family to emigrate to the United States. In July 1878, Davitt made a trip to visit them and raise money through a lecture tour to bring his mother and youngest sister back to Ireland (his father had since died). Upon his arrival in New York, he was welcomed by the United States-based republican organisation Clan na Gael and its leader, John Devoy. In its first such venture of the kind, the Clan