In large part our political history is but the reflection of the economic motives and economic changes in the national life. Thus the American Revolution arose out of resistance to England's trade regulations, commercial restrictions, and attempted taxation of the colonies. The War of 1812 was brought on by interference with American commerce on the high seas. The Mexican War was the result of the colonization of Texan territory by American settlers and the desire of powerful interests to extend the area of land open to slavery. The Civil War arose more immediately out of a difference of opinion as to the rights of states to be supreme in certain fields of legislation, but back of this political issue was the economic problem of slave labor. Illustrations of this kind, which may be indefinitely multiplied, do not prove that the material, economic changes are the cause of all other changes, political, scientific, and ethical; for in many cases the economic changes themselves appear to be the results of changes of the other kinds. There is a constant action and reaction between economic forces and other forces and interests in human society, and the needs of economic adjustment are constantly changing in nature. § 3. #Present-day problems: main subjects#. The particular economic problems in America at this time are determined by the whole complex economic and social situation. Two main factors in this may be distinguished: the objective and the subjective, or the material environment and the population composing the nation. The one is what we have, the other is what we are, as a people. These factors are closely related; for what we are as a people (our tastes, interests, capacities, achievements) depends largely on what we have, and what we have (our wealth and incomes) depends largely on what we are. We may consider the following phases; the first two of the objective factor, and the last two of the subjective factor. (a) The basic material resources, consisting of the materials of the earth's surface and the natural climatic conditions which together provide the physical conditions necessary for human existence, and which furnish the stuff out of which men can create new forms of wealth. (b) The industrial equipment, consisting of all those artificial adaptations and improvements of the original resources by which men fit nature better to do their will. These two (a and b) become more and more difficult to distinguish in settled and civilized communities, and become blended into one mass of valuable objects, the wealth of the nation. (c) The social system under which men live together, make use of wealth and of their own services, and exchange economic goods. (d) The people, considered with reference to their number, race, intelligence, education, and moral, political, and economic capacity.