Still more would he have been astounded and elated could he have foreseen, beyond all advances in material production, the unbroken strength of that political structure which he had so grand a share in rearing.  Into this very region where we are this afternoon, swept wave after wave of immigration; English from Virginia flowed over the border, bringing English traits, literature, habits of mind; Scots, or Scots-Irish, originally from Ulster, flowed in from Central Pennsylvania; Catholics from Southern Ireland; new hosts from Southern and East Central Europe.  This is not the Fourth of July.  But people of every school would agree that it is no exuberance of rhetoric, it is only sober truth to say that the persevering absorption and incorporation of all this ceaseless torrent of heterogenous elements into one united, stable, industrious, and pacific State is an achievement that neither the Roman Empire nor the Roman Church, neither Byzantine Empire nor Russian, not Charles the Great nor Charles the Fifth nor Napoleon ever rivaled or approached.

We are usually apt to excuse the slower rate of liberal progress in our Old World by contrasting the obstructive barriers of prejudice, survival, solecism, anachronism, convention, institution, all so obstinately rooted, even when the branches seem bare and broken, in an old world, with the open and disengaged ground of the new.  Yet in fact your difficulties were at least as formidable as those of the older civilizations into whose fruitful heritage you have entered.  Unique was the necessity of this gigantic task of incorporation, the assimilation of people of divers faiths and race.  A second difficulty was more formidable still—­how to erect and work a powerful and wealthy State on such a system as to combine the centralized concert of a federal system with local independence, and to unite collective energy with the encouragement of individual freedom.

This last difficulty that you have so successfully up to now surmounted, at the present hour confronts the mother country and deeply perplexes her statesmen.  Liberty and union have been called the twin ideas of America.  So, too, they are the twin ideals of all responsible men in Great Britain; altho responsible men differ among themselves as to the safest path on which to travel toward the common goal, and tho the dividing ocean, in other ways so much our friend, interposes, for our case of an island State, or rather for a group of island States, obstacles from which a continental State like yours is happily altogether free.

Nobody believes that no difficulties remain.  Some of them are obvious.  But the common-sense, the mixture of patience and determination that has conquered risks and mischiefs in the past, may be trusted with the future.