The American Revolution and the Irish revolutionary renaissance--the one
achieved by a long and bitter war, the other without
bloodshed--originated and culminated together, were derived from the
same sources, and ran their course in close connection. In Ireland the
movement was exclusively Protestant, in America unsectarian; but in both
cases finance was the lever of emancipation. America, resenting the
commercial restrictions imposed by the Mother Country, but not, until
passion had obscured all landmarks, contesting their abstract justice,
and suffering no great material harm from their incidence, fought for
the principle of self-taxation--a principle which did, of course,
logically include, as the Americans instinctively felt, that of
commercial freedom. Ireland, harassed by commercial restrictions far
more onerous, naturally regarded their abolition as vital, and the
control of internal taxation as subsidiary. Apart from concrete
grievances, both countries had to fear an unlimited extension of British
claims founded on the all-embracing Declaratory Acts of 1719 and 1766.

Unfortunately for herself, Ireland for seventy years or more had been
steadily supplying America with the human elements of resistance in
their most energetic and independent form, and robbing herself
proportionately Approximately, how many Protestants belonging mainly to
Ulster, whether through eviction from the land, industrial unemployment,
or disgust at social and political ostracism, left Ireland for America
in the course of the eighteenth century, it is impossible to say; but
the number, both relatively to population and relatively to the total
emigration, Catholic and Protestant, to all parts of the world, was
undoubtedly very large. Mr. Egerton, in his "Origin and Growth of the
English Colonies," reckons that in 1775 a sixth part of the thirteen
insurrectionary Colonies was composed of Scots-Irish exiles from Ulster,
and that half the Protestant population of that Province emigrated to