between the political parties in respect to it, the diversity of the views of the
 members of this court in regard to its constitutional aspects, and the constant
 recurrence of the subject in the Houses of Congress, fixed the attention of all on
 the future relation of this acquired territory to the United States. Had Congress
 intended to take the important step of changing the treaty status of Porto Rico by
 incorporating it into the Union, it is reasonable to suppose that it would have done
 so by the plain declaration, and would not leave it to mere inference. Before the
 question became acute at the close of the Spanish War, the distinction between
 acquisition and incorporation was not regarded as important, or at least it was not
 fully understood and had not aroused great controversy. Before that, the
 purpose of Congress might well be a matter of mere inference from various
 legislative acts; but in these latter days, incorporation is not to be assumed
 without express declaration, or an implication so strong as to exclude any other
 view.39
 Referring to the fact that, in the Jones Act, the bill of rights included all the guaranties of the
 Federal Constitution except those relating to grand and petit juries he argued that:

 If it was intended to incorporate Porto Rico into the Union by this act, which would
 'ex proprio vigore' make applicable the whole Bill of Rights of the Constitution to
 the Island, why was it thought necessary to create for it a Bill of Rights and
 carefully exclude trial by jury? In the very forefront of the act is this substitute for
 incorporation and application of the Bill of Rights of the Constitution. This seems
 to us a conclusive argument against the contention of counsel for the plaintiff in
 error.40

 The view of the reasons underlying the non-incorporation of our insular possessions was thus
 stated by Chief Justice Taft:

 The jury system needs citizens trained to the exercise of the responsibility of
 jurors. In common-law countries centuries of tradition have prepared a
 conception of the impartial attitude jurors must assume. The jury system
 postulated a conscious duty of participation in the machinery of justice which it is
 hard for people not brought up in fundamentally popular government at once to
 acquire. One of its greatest benefits is in the security it gives the people that
 they, as jurors actual or possible, being part of the judicial system of the country
 can prevent its arbitrary use or abuse. Congress has thought that a people like
 the Filipinos or the Porto Ricans, trained to a complete judicial system which
 knows no juries, living in compact and ancient communities, with definitely
 formed customs and political conceptions, should be permitted themselves to
 determine how far they wish to adopt this institution of Anglo-Saxon origin, and
 when.41

We have here the same thought as that expounded in Downes v. Bidwellas to the non-fundamental
character of jury trial.

 Thus, after nearly a quarter of a century of judicial debate, the doctrine of incorporation found
formal lodgment in our public law. This legal fiction has, in effect, been used to declare that the
Constitution does not follow the flag, and that trial by jury is not a fundamental right. The inhabitants of
these possessions may only wait for civil liberties to be extended to them according to the will of
Congress. The parallel with the old British Empire is suggestive; and the government at Washington,
unlike that of England, has been reluctant to admit the existence of an Empire. No colonial office has been
established or colonial secretary appointed, and the administration of one possession may differ
considerably with that of another.

 The doctrine of incorporation is clearly contrary to the principle of equality set forth in the
Ordinance of 1787 for the Northwest Territory. The rights extended to the territorial inhabitants by that