Out of the economic and political circumstances which have just been described, there were emerging between 1865 and 1875 a wide variety of national problems. Such questions were those concerning the proper relation between the government and the railroads and industrial enterprises; the welfare of the agricultural and wage-earning classes; the assimilation of the hordes of immigrants; the conservation of the resources of the nation in lumber, minerals and oil; the tariff, the financial obligations of the government, the reform of the civil service, and a host of lesser matters.