The discontent and grievances of the Irish had a vivid historical background in their own country. There were four principal causes which induced the transplanting of the race: rebellion, famine, restrictive legislation, and absentee landlordism. Every uprising of this bellicose people from the time of Cromwell onward had been followed by voluntary and involuntary exile. It is said that Cromwell's Government transported many thousand Irish to the West Indies. Many of these exiles subsequently found their way to the Carolinas, Virginia, and other colonies. After the great Irish rebellion of 1798 and again after Robert Emmet's melancholy failure in the rising of 1803 many fled across the sea. The Act of Union in 1801 brought "no submissive love for England," and constant political agitations for which the Celtic Irish need but little stimulus have kept the pathway to America populous. The harsh penal laws of two centuries ago prescribing transportation and long terms of penal servitude were a compelling agency in driving the Irish to America. Illiberal laws against religious nonconformists, especially against the Catholics, closed the doors of political advancement in their faces, submitted them to humiliating discriminations, and drove many from the island. Finally, the selfish Navigation Laws forbade both exportation of cattle to England and the sending of foodstuffs to the colonies, dealing thereby a heavy blow to Irish agriculture. These restrictions were followed by other inhibitions until almost every industry or business in which the Irish engaged was unduly limited and controlled. It should, however, not be forgotten that these restrictions bore with equal weight upon the Ulster settlers from Scotland and England, who managed somehow to endure them successfully. Absentee landlordism was oppressive both to the cotter's body and to his soul, for it not only bound him to perpetual poverty but kindled within him a deep sense of injustice. The historian, Justin McCarthy, says that the Irishman "regarded the right to have a bit of land, his share, exactly as other people regard the right to live." So political and economic conditions combined to feed the discontent of a people peculiarly sensitive to wrongs and swift in their resentments.