[From the opening paragraph]

The question, "What constitutes the area of the United States?" is by no means a simple one. Our jurisdiction extends to a line three nautical miles from the shore, but this strip of sea cannot properly be regarded as a portion of the country. Supposing our boundary to be restricted to the sea-coast, there remains a question regarding the bays and estuaries of the sea. To what extent should the coast line be followed strictly, and where should we begin to jump across the indentations made by the sea? In this matter one can only follow his own judgment, making in each case as natural a decision as possible, as no criterion whatever can be established. In this way I have defined the coast limits, showing by the red line on the accompanying map what I have taken as the gross area of the country and of the states, severally.