In May, 1800, on the reorganization of President Adams's Cabinet, Marshall unexpectedly received the appointment of Secretary of War. He declined it; but the office of Secretary of State also having become vacant, he accepted that position, which he held till the fourth of the following March. Of his term as Secretary of State, which lasted less than ten months, little has been said; nor was it distinguished by any event of unusual importance, save the conclusion of the convention with France of Sept. 30, 1800, the negotiation of which, at Paris, was already in progress, under instructions given by his predecessor, when he entered the Department of State. The war between France and Great Britain, growing out of the French Revolution, was still going on. The questions with which he was required to deal were not new; and while he exhibited in the discussion of them his usual strength and lucidity of argument, he had little opportunity to display a capacity for negotiation. Only a few of his State papers have been printed, nor are those that have been published of special importance. He gave instructions to our minister to Great Britain, in relation to commercial restrictions, impressments, and orders in council violative of the law of nations; to our minister to France, in regard to the violations of neutral rights perpetrated by that government; and to our minister to Spain, concerning infractions of international law committed, chiefly by French authorities, within the Spanish jurisdiction. Of these various State papers the most notable was that which he addressed on Sept. 20, 1800, to Rufus King, then United States Minister at London. Reviewing in this instruction the policy which his government had pursued, and to which it still adhered, in the conflict between the European powers, he said:--

"The United States do not hold themselves in any degree responsible to France or to Britain for their negotiations with the one or the other of these powers; but they are ready to make amicable and reasonable explanations with either.... It has been the object of the American government, from the commencement of the present war, to preserve between the belligerent powers an exact neutrality.... The aggressions, sometimes of one and sometimes of another belligerent power, have forced us to contemplate and prepare for war as a probable event. We have repelled, and we will continue to repel, injuries not doubtful in their nature and hostilities not to be misunderstood. But this is a situation of necessity, not of choice. It is one in which we are placed, not by our own acts, but by the acts of others, and which we [shall] change so soon as the conduct of others will permit us to change it."

For a month Marshall held both the office of Secretary of State and that of Chief Justice; but at the close of John Adams' administration he devoted himself exclusively to his judicial duties, never performing thereafter any other public service, save that late in life he acted as a member of the convention to revise the Constitution of Virginia.

It is an interesting fact that, prior to his appointment as Chief Justice, Marshall had appeared only once before the Supreme Court, and on that occasion he was unsuccessful. This appearance was in the case of Ware v. Hylton, which was a suit brought by a British creditor to compel the payment by a citizen of Virginia of a pre-Revolutionary debt, in conformity with the stipulations of the treaty of peace. During the Revolutionary War various States, among which was Virginia, passed acts of sequestration and confiscation, by which it was provided that, if the American debtor should pay into the State treasury the amount due to his British creditor, such payment should constitute an effectual plea in bar to a subsequent action for the recovery of the debt. When the representatives of the United States and Great Britain met in Paris to negotiate for peace, the question of the confiscated debts became a subject of controversy, especially in connection with that of the claims of the loyalists for the confiscation of their estates. Franklin and Jay, though they did not advocate the policy of confiscating debts, hesitated, chiefly on the ground of a want of authority in the existing national government to override the acts of the States. But when John Adams arrived on the scene, the situation soon changed. By one of those dramatic strokes of which he was a master, he ended the discussion by suddenly declaring, in the presence of the British plenipotentiaries, that, so far as he was concerned, he "had no notion of cheating anybody;" that the question of paying debts and the question of compensating the loyalists were two; and that, while he was opposed to compensating the loyalists, he would agree to a stipulation to secure the payment of debts. It was therefore provided, in the fourth article of the treaty, that creditors on either side should meet with no lawful impediment to the recovery in full sterling money of bona fide debts contracted prior to the war. This stipulation is remarkable, not only as the embodiment of an enlightened policy, but also as perhaps the strongest assertion to be found in the acts of that time of the power and authority of the national government. Indeed, when the British creditors, after the establishment of peace, sought to proceed in the State courts, they found the treaty unavailing, since those tribunals held themselves still to be bound by the local statutes. In order to remove this difficulty, as well as to provide a rule for the future, there was inserted in the Constitution of the United States the clause expressly declaring that treaties then made, or which should be made, under the authority of the United States, should be the supreme law of the land, binding on the judges in every State, anything in the Constitution or laws of any State to the contrary notwithstanding.

On the strength of this provision, the question of the debts was raised again, and was finally brought before the Supreme Court. Marshall appeared for the State of Virginia, to oppose the collection of the debt. He based his contention on two grounds: first, that by the law of nations the confiscation of private debts was justifiable; second, that, as the debt had by the law of Virginia been extinguished by its payment into the State treasury, and had thus ceased to be due, the stipulation of the treaty was inapplicable, since there could be no creditor without a debtor. It is not strange that this argument was unsuccessful. While it doubtless was the best that the cause admitted of, it may perhaps serve a useful purpose as an illustration of the right of the suitor to have his case, no matter how weak it may be, fully and fairly presented for adjudication. On the question of the right of confiscation the judges differed, one holding that such a right existed, while another denied it, two doubted, and the fifth was silent. But as to the operation of the treaty, all but one agreed that it restored to the original creditor his right to sue, without regard to the original validity or invalidity of the Virginia statute.

When Marshall took his seat upon the bench, the Supreme Court, since its organization in 1790, had rendered only six decisions involving constitutional questions. Of his three predecessors, Jay, Rutledge, and Ellsworth, the second, Rutledge, after sitting one term under a recess appointment, retired in consequence of his rejection by the Senate; and neither Jay nor Ellsworth, though both were men of high capacity, had found in their judicial station, the full importance of which was unforeseen, an opportunity for the full display of their powers, either of mind or of office. The coming of Marshall to the seat of justice marks the beginning of an era which is not yet ended, and which must endure so long as our system of government retains the essential features with which it was originally endowed. With him really began the process, peculiar to our American system, of the development of constitutional law by means of judicial decisions, based upon the provisions of a fundamental written instrument and designed for its exposition and enforcement. By the masterful exercise of this momentous jurisdiction, he profoundly affected the course of the national life and won in the knowledge and affections of the American people a larger and higher place than ever has been filled by any other judicial magistrate.

From 1801 to 1835, in the thirty-four years during which he presided in the Supreme Court, sixty-two decisions were rendered involving constitutional questions, and in thirty-six of these the opinion of the court was written by Marshall. In the remaining twenty-six the preparation of the opinions was distributed among his associates, who numbered five before 1808 and after that date six. During the whole period of his service, his dissenting opinions numbered eight, only one of which involved a constitutional question. Nor was the supremacy which this record indicates confined to questions of constitutional law. The reports of the court during Marshall's tenure fill thirty volumes, containing 1,215 cases. In ninety-four of these no opinions were filed, while fifteen were decided "by the court." In the remaining 1,106 cases the opinion of the court was delivered by Marshall in 519, or nearly one-half.

A full review of the questions of constitutional law decided by the Supreme Court during Marshall's term of service would involve a comprehensive examination of the foundations on which our constitutional system has been reared; but we may briefly refer to certain leading cases by which fundamental principles were established.

In one of his early opinions he discussed and decided the question whether an Act of Congress repugnant to the Constitution is void. This question was then by no means free from difficulty and doubt. The framers of the Constitution took care to assure its enforcement by judicial means against inconsistent State action, by the explicit provision that the Constitution itself, as well as Federal statutes and treaties, should be the "supreme law" of the land, and as such binding upon the State judges, in spite of anything in the local laws and constitutions. But as to the power of the courts to declare unconstitutional a Federal statute, the instrument was silent. There is reason to believe that this silence was not unintentional; nor would it be difficult to cite highly respectable opinions to the effect that the courts, viewed as a co-ordinate branch of the government, have no power to declare invalid an Act of the Legislature, unless they possess express constitutional authority to that effect. We have seen that Marshall expressed in the discussions of the Virginia convention a contrary view; but it is one thing to assert an opinion in debate and another thing to declare it from the bench, especially in a case involved in or related to political contests; and such a case was Marbury v. Madison.

Marbury was a citizen of the District of Columbia, who had been appointed as a justice of the peace by John Adams, just before his vacation of the office of President. It was one of the so-called "midnight" appointments of President Adams, which became a subject of heated political controversy. It was alleged that Marbury's commission had been made out, sealed, and signed, but that Mr. Madison, who immediately afterwards became Secretary of State, withheld it from him. Marbury therefore applied to the Supreme Court for a writ of mandamus to compel its delivery. In the course of the judgment, which was delivered by Marshall, opinions were expressed on certain questions the decision of which was not essential to the determination of the case, and into these it is unnecessary now to enter, although one of them has been cited and acted upon as a precedent. But on one point the decision of the court was requisite and fundamental, and that was the point of jurisdiction. It was held that the court had no power to grant the writ, because the Federal statute by which the jurisdiction was sought to be conferred was repugnant to the Constitution of the United States. This was the great question decided, and it was a decision of the first importance, since its assertion of the final authority of the judicial power, in the interpretation and enforcement of our written constitutions, came to be accepted almost as an axiom of American jurisprudence. In the course of his reasoning, Chief Justice Marshall expressed in terms of unsurpassed clearness the principle which lay at the root of his opinion. "It is," he declared, "emphatically the province and duty of the judicial department to say what the law is.... If two laws conflict with each other, the courts must decide on the operation of each.... If, then, the courts are to regard the Constitution, and the Constitution is superior to any ordinary Act of the Legislature, the Constitution and not such ordinary Act must govern the case to which they both apply. Those, then, who controvert the principle that the Constitution is to be considered in court as a paramount law, are reduced to the necessity of maintaining that courts must close their eyes on the Constitution and see only the law. This doctrine would subvert the very foundation of all written constitutions." In subsequently applying this rule, Marshall affirmed that the courts ought never to declare an Act of Congress to be void "unless upon a clear and strong conviction of its incompatibility with the Constitution." Nevertheless, the power has been constantly and frequently exercised; and there can be no doubt that from its exercise the Supreme Court of the United States derives a political importance not possessed by any other judicial tribunal.