The growth of the nation is indicated in an external or super-ficial way by the increase in area, population, and commercial agencies, and that growth has been unprecedented in uniformity and rapidity, as indicated by the lines in the diagram ; yet the essential elements of American growth cannot be expressed in square miles of area, in linear miles of railway and waterway, in transportation tonnage, or in other definite units ; the real growth lies in the development of enterprise„ intellectual and moral and physical vigor, or, in brief, intelligent individuality. The strength of America is indeed faintly suggested by broad territorial expanse, teeming millions of people, and half the railways of the world ; the real strength lies in the immeasurable capabilities of individuals, who have already made noble conquest of nature’s forces ; and there are no units for measuring the spontaneous powers of freemen united by common impulse in the common task of elevating mankind and bettering the world. While there is no direct way of measuring the individualitymuch less the unityof the American people, there are certain values indicating this quality even more clearly than area or population ; one of these is wealth, individual and collective.* Unfortunately, early figures for the expression of wealth are lacking, but since 1850 wealth has increased more rapidly than any other measurable factor in national progress, as illustrated by the remaining curves in the diagram. In the last half-century the population of the United States has more than tripled, yet the wealth has more than thrice tripled, and the per capita wealth of the American citizen has risen far above the corresponding value for the other countries. This element of growth, too, is correlated with the increase in area, especially the epochal accession of half a century ago ; for, although the statistics are wanting for the first half of the century. mere inspection of the later curves shows that the rate of increase must have been at least doubled or tripled almost immediately after the acquisition of Texas and California.