One thing is certain, that the discovery of America opened a new field for industry and enterprise to all the discontented and impoverished and oppressed Europeans who emigrated.  At first they emigrated to dig silver and gold.  The opening of mines required labor, and miners were obliged to part with their gold for the necessaries of life.  Thus California in our day has become peopled with farmers and merchants and manufacturers, as well as miners.  Many came to America expecting to find gold, and were disappointed, and were obliged to turn agriculturists, as in Virginia.  Many came to New England from political and religious motives.  But all came to better their fortunes.  Gradually the United States and Canada became populated from east to west and from north to south.  The surplus population of Europe poured itself into the wilds of America.  Generally the emigrants were farmers.  With the growth of agricultural industry were developed commerce and manufactures.  Thus, materially, the world was immensely benefited.  A new continent was opened for industry.  No matter what the form of government may be,—­I might almost say no matter what the morals and religion of the people may be,—­so long as there is land to occupy, and to be sold cheap, the continent will fill up, and will be as densely populated as Europe or Asia, because the natural advantages are good.  The rivers and the lakes will be navigated; the products of the country will be exchanged for European and Asiatic products; wealth will certainly increase, and increase indefinitely.  There is no calculating the future resources and wealth of the New World, especially in the United States.  There are no conceivable bounds to their future commerce, manufactures, and agricultural products.  We can predict with certainty the rise of new cities, villas, palaces, material splendor, limited only to the increasing resources and population of the country.  Who can tell the number of miles of new railroads yet to be made; the new inventions to abridge human labor; what great empires are destined to rise; what unknown forms of luxury will be found out; what new and magnificent trophies of art and science will gradually be seen; what mechanism, what material glories, are sure to come?  This is not speculation.  Nothing can retard the growth of America in material wealth and glory.  The splendid external will call forth more panegyrics than the old Roman world which fancied itself eternal.  The tower of the new Babel will rise to the clouds, and be seen in all its glory throughout the earth and sea.  No Fourth of July orator ever exaggerated the future destinies of America in a material point of view.  No “spread-eagle” politician even conceived what will be sure to come.