Walsh were effectively the only national leaders; they worked closely with Anna Parnell, who provided assistance. While in the United States he toured the country giving speeches as far afield as San Francisco. The Liberal government responded to the land agitation with the Protection of Persons and Property Act 1881, an extension of previous Coercion Acts, which would enable the internment without trial of those suspected of involvement in the Land War. In their fight against the act, the IPP MPs reached new heights of obstruction, but were ultimately unable to block it. It was Davitt's idea to set up a Ladies' Land League to continue their work when the male Land League leaders were arrested, as expected. On 3 February 1881, Davitt's ticket of leave was rescinded; he was arrested in Dublin and returned to Millbank Prison in England. The IPP MPs protested so strongly in Parliament that thirty-six were expelled. Almost a thousand people were arrested under the Coercion Act, but agrarian crime continued to increase. In April, the government introduced the Land Law (Ireland) Act 1881, which Liberal minister Joseph Chamberlain described as removing "the chief grievance" of the agitators by granting many of their demands: fair rent, free sale, and fixity of tenure. As it fell short of peasant proprietorship, it was criticised as insufficient by the Land League, although Davitt later claimed that it had "struck a mortal blow at Irish landlordism". Davitt served most of his second term of incarceration at Portland Prison, under much better conditions than previously, owing to his fame and concern over his health. He was allowed books and continued to study agrarian theory. He became enamoured of the ideas of Henry George and abandoned the idea of peasant proprietorship in favour of land nationalisation. He also read many liberal thinkers, such as John Stuart Mill, Adolphe Thiers, Augustin Thierry, François Guizot, William Edward Hartpole Lecky, and Thomas Babington Macaulay. In an 1882 by-election, he was elected Member of Parliament for Meath but was disqualified because he was in prison. In October 1881, Parnell and other IPP leaders were also arrested. The Land League responded with the No Rent Manifesto on 18 October, urging tenant farmers not to pay rent until they were released. Two days later, the British government banned the Land League. Davitt and his allies were released from prison in May 1882, according to the Kilmainham Treaty