He shall have Powers, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur . . . . [U.S. Constitution, Article II, section 2, clause 2]
The delegates to the Constitutional Convention first considered the treaty-making power when the Committee of Detail submitted its draft Constitution on August 6. Article IX, section 1 stated: “The Senate of the United States shall have power to make treaties, and to appoint Ambassadors, and Judges of the Supreme Court.” Several delegates opposed granting the Senate sole control over treaty-making. While some wanted the executive to have that responsibility, others advocated involving the entire legislature in the process. Small-state delegates, however, preferred the Committee of Detail’s treaty clause because it gave each state an equal say in the adoption or rejection of treaties.
As they debated the treaty-making clause, the delegates again turned to familiar precedents. In Great Britain treaties were negotiated by the king and, in certain cases, had to be approved by a majority vote in Parliament. The Continental Congress, which had no executive officer, dispatched agents to negotiate treaties, but the treaties went into effect only after two-thirds (nine out of thirteen) of the states gave their approval. This process was further complicated by the states’ ability to enter into their own treaties with foreign powers.
On September 4 the Committee of Eleven reported a revised proposal that appeased many of the delegates by sharing the treaty-making power between the president and the Senate: “The President by and with the advice and Consent of the Senate, shall have power to make Treaties.” The delegates unanimously approved the clause on September 7, but it was later amended to include: “But no treaty shall be made without the consent of two thirds of the members present.”
The Constitution’s treaty clause continued to stir debate as the states considered ratification. As one of the clause’s strongest proponents, New York’s Alexander Hamilton, in The Federalist No. 75, defended the treaty-making provisions as the “best digested and most unexceptionable parts” of the Constitution. “It must indeed be clear,” he wrote, “that the joint possession of the power in question, by the President and Senate, would afford a greater prospect of security, than the separate possession of it by either of them.” He also justified placing this power in the Senate rather than the House: “The fluctuating and, taking its future increase into the account, the multitudinous composition of that body, forbid us to expect in it those qualities which are essential to the proper execution of such a trust.”