"Any given case must be treated on its special merits. Each community should be required to deal with all that is of merely local interest; and nothing should be undertaken by the Government of the whole country which can thus wisely be left to local management. But those functions of government which no wisdom on the part of the States will enable them satisfactorily to perform must be performed by the National Government. We are all Americans; our common interests are as broad as the continent; the most vital problems are those that affect us all alike. The regulation of big business, and therefore the control of big property in the public interest, are preeminently instances of such functions which can only be performed efficiently and wisely by the Nation; and, moreover, so far as labor is employed in connection with inter-State business, it should also be treated as a matter for the National Government. The National power over inter-State commerce warrants our dealing with such questions as employers' liability in inter-State business, and the protection and compensation for injuries of railway employees. The National Government of right has, and must exercise its power for the protection of labor which is connected with the instrumentalities of inter-State commerce."