The early practice and understanding of the government on the issue of warmaking closely conformed to the constitutional framework. There was, throughout the nineteenth century, no instance of a presidential assertion of a unilateral warmaking power. But there were disputes in the margins.
In 1793 war broke out between Great Britain and France. President George Washington declared that the Treaty of Alliance of 1778 did not obligate the United States to defend French territory in America, and he issued a proclamation of neutrality. Whether this power belonged to the president or Congress set off a remarkable debate between Hamilton and Madison. In a series of articles signed "Pacificus," Hamilton defended the substance of the policy as well as the president's unilateral authority to promulgate it. Hamilton acknowledged that "the legislature have the right to make war on the one hand," but it remained "the duty of the Executive to preserve peace till war is declared." In the fulfillment of that duty, Hamilton argued, the president "must necessarily possess a right of judging what is the nature of the obligations which the treaties of the country impose on the government." By this time, France was involved in several wars, and Hamilton's concerns about the force and nature of the treaties was evident: Did they obligate the United States to assist the French in their foreign adventures? He properly denied the existence of any such ironclad obligation, but his view that the president possessed discretionary authority, as part of his "duty" to preserve peace "till war is declared," triggered a response from Madison, who wrote under the pseudonym of "Helvidius" and asserted that if Washington's proclamation were valid, it meant that the president had usurped congressional power to decide between a state of peace or a state of war. Despite this difference, both agreed that the power to initiate war is vested in Congress. Madison wrote that the "executive has no right, in any case, to decide the question, whether there is or is not cause for declaring war; that the right of convening and informing Congress, whenever such a question seems to call for a decision, is all the right which the Constitution has deemed requisite or proper." It is to be emphasized that throughout their lives both Hamilton and Madison maintained the doctrine that it is for Congress alone to initiate hostilities. That agreement reflected the understanding of the war clause throughout the nineteenth century. In fact, presidents—Washington, Adams, and Jefferson among them—were particularly careful to avoid military actions that might encroach upon the congressional warpower.
In 1798 France repeatedly raided and seized American vessels. When asked whether a new law that increased the size of the navy authorized the president to initiate hostilities, Hamilton stated that he had not seen the law and that, if it did not grant the president any new authority but left him "at the foot of the Constitution," then the president had only the power to "employ the ships as convoys, with authority to repel force by force (but not to capture) and to repress hostilities within our waters, including a marine league from our coasts. Anything beyond this must fall under the idea of reprisals, and requires the sanctions of that department which is to declare or make war. "
Contrary to the claim that President John Adams engaged in an exercise of unilateral warmaking in the Quasi-War with France (1798–1800), the facts demonstrate that the war was clearly authorized by Congress, which debated the prospect of war and passed some twenty statutes permitting it to be waged. Moreover, Adams took absolutely no independent action. In Bas v. Tingy (1800), the Supreme Court held that the body of statutes enacted by Congress had authorized imperfect, or limited, war. In Talbot v. Seeman (1801), a case that arose from issues in the Quasi-War, Chief Justice John Marshall wrote for the Court, "The whole powers of war being, by the Constitution of the United States, vested in Congress, the acts of that body can alone be resorted to as our guides in this inquiry." In Little v. Barreme (1804), Marshall emphasized the control that Congress can wield over the president as commander in chief. One of the statutes passed by Congress during the Quasi-War with France authorized the president to seize vessels sailing to French ports. President Adams issued an order directing American ships to capture vessels sailing to or from French ports, but in the opinion for the Court, Marshall held that Adams's order had exceeded his authority since congressional policy set forth in the statute was superior to presidential orders inconsistent with the statute. Subsequent judicial holdings have reiterated the fact that the commander in chief may be controlled by statute.
As president, Thomas Jefferson acknowledged that his powers of war were limited to defensive actions. In his first annual message to Congress in 1801 he reported the arrogant demands made by the pasha of Tripoli. Unless the United States paid tribute, the pasha threatened to seize American ships and citizens. Jefferson responded by sending a small squadron to the Mediterranean to protect against the threatened attack. He then asked Congress for further guidance, stating he was "unauthorized by the Constitution, without the sanction of Congress, to go beyond the line of defense." It was left to Congress to authorize "measures of offense also." Jefferson's understanding of the war clause underwent no revision. In 1805 he informed Congress of the dispute with Spain over the boundaries of Louisiana and Florida. Jefferson warned that Spain evidenced an "intention to advance on our possessions until they shall be repressed by an opposing force. Considering that Congress alone is constitutionally invested with the power of changing our condition from peace to war, I have thought it my duty to await their authority for using force."
Other early presidents, including Washington, Madison, James Monroe, and Andrew Jackson, also refused to exercise offensive military powers without authorization from Congress, which they understood to be the sole repository of the power to initiate war. There was no departure from this understanding of the war clause throughout the nineteenth century. In 1846 President James K. Polk ordered an army into a disputed border area between Texas and Mexico. One of its patrols was attacked by Mexican forces, which were defeated by the U.S. soldiers. In a message to Congress, Polk offered the rationale that Mexico had invaded the United States, which prompted Congress to declare war. If Polk's rationale was correct, then his action could not be challenged on constitutional grounds, for it was well established that the president had the authority to repel sudden attacks. If, however, he was disingenuous—if he had in fact initiated military hostilities—then he had clearly usurped the warmaking power of Congress. It is worth noticing that he made no claim to constitutional power to make war.
Although Congress declared war, the House of Representatives censured Polk for his actions because the war had been "unnecessarily and unconstitutionally begun by the President of the United States." It seemed evident that Polk had dispatched troops into the disputed area for the purpose of precipitating war by provoking a Mexican attack on American soldiers. His manipulative efforts were effective. Representative Abraham Lincoln voted with the majority against Polk. As president, Lincoln maintained that only Congress could authorize the initiation of hostilities. None of his actions in the Civil War, including the suspension of habeas corpus, the appropriation of funds from the U.S. treasury, or his decision to call forth regiments from state militias, each of which was eventually retroactively authorized by Congress, constituted a precedent for presidential initiation of war. Moreover, in the Prize Cases (1863), the Supreme Court upheld Lincoln's blockade against the rebellious Confederacy as a constitutional response to a sudden invasion that began with the attack on Fort Sumter. The Court stated that the president, as commander in chief, "has no power to initiate or declare war either against a foreign nation or a domestic state." Nevertheless, in the event of invasion by a foreign nation or a state, the president was not only authorized "but bound to resist force by force. He does not initiate the war, but is bound to accept the challenge without waiting for any special legislative authority." According to the Court, the president had to meet the crisis in the shape it presented itself "without waiting for Congress to baptize it with a name; and no name given to it by him or them could change the fact."