Although most citizens accepted the principle of isolationism, scattered voices throughout the nineteenth century called for a more cooperative stance toward the world. As early as the 1830s the American Peace Society, under the direction of William Ladd, sponsored essay contests concerning international organization, and in 1840 Ladd utilized many of the ideas in drafting his wellknown Essay on a Congress of Nations. His proposal for both a political body and a judicial agency gained considerable public notice through petition and educational campaigns during the ensuing years. After Ladd's death in 1841, Elihu Burritt, a reformer known as "The Learned Blacksmith," presented the congress of nations program to European pacifists with such regularity that they referred to it as the "American idea."
The Civil War in America (1861–1865) and conflicts in Europe (1854–1856, 1870–1871) undermined the peace movement, but a developing interest in the law of nations kept alive the concept of global cooperation during the last third of the century. Several societies emerged to promote the codification of international rules of behavior and to encourage the settlement of disputes through arbitration by a third party. These were not new ideas, but leading citizens in many nations around the turn of the twentieth century seized upon the arbitration concept to guarantee a warless world.
This activity contributed substantially to the evolution of thought concerning an international organization. As countries signed arbitration accords, men—and a few women—began to think beyond such limited agreements. Agencies would be needed to implement the treaties; laws would have to be codified. As John Westlake, an English law professor, observed, "When we assert that there is such a thing as International Law, we assert that there is a society of States; when we recognize that there is a society of States, we recognize that there is International Law."
The arbitration settlement in 1871–1872 of the Alabama Claims, an Anglo-American dispute over damages caused by Confederate cruisers, led to the signing of many other arbitration agreements during the next four decades. Most were disputes involving monetary and boundary claims and questions arising under treaty clauses; this discouraged pacifists, who hoped to see accords calling for all controversies to be arbitrated. They rallied to promote their goal, gaining public endorsement in the 1890s. The Lake Mohonk (New York) Conference on International Arbitration, which began in 1895 and met annually through 1916, united American civic, business, religious, and educational leaders in a quest to institutionalize arbitration. Proponents recognized that the Senate would not subscribe to unlimited agreements, so they agreed that matters involving national honor and vital interests be exempted. Their support resulted in the Olney-Pauncefote Treaty with Great Britain in 1897, which called for the arbitration of monetary and territorial differences. As expected, the Senate exempted disputes affecting national interest and honor, and then insisted that the Senate have authority to exempt from arbitration any dispute submitted for settlement. Even these safeguards did not satisfy the extreme isolationists. After adding yet other reservations, the Senate refused to ratify the treaty.
These developments had a lasting impact upon American internationalist thought. First, arbitration accords encouraged the exploration of cooperative methods of resolving disputes and breached barriers that had kept statesmen from previously examining such subjects. Second, these experiences warned internationalists that they must be cautious about proposals for a union of nations. It was quite clear by the time that the United States fought Spain in 1898 that Washington would not assume obligations that would weaken its sovereignty or jeopardize interests deemed vital to its welfare. Finally, the advances in arbitration influenced discussions at the first genuine international assembly of nations, the Hague Conference of 1899.