The 1898 Treaty of Paris ended the Spanish–American War, with Spain ceding the Philippines to the United States. Islam had arrived in the Philippines before the Spanish. Spain had conquered the northern islands, and the southern islands had become Muslim strongholds. The Spanish cession included the islands of Mindanao and the Sulu Archipelago, and the ceded territory included the islands of the Sultanate of Sulu located in the Philippine archipelago where slavery and piracy had for centuries been practiced by the Moros. The Spanish had established coastal garrisons but had never controlled the jungle interiors of the islands.
In 1899, U.S. Brigadier General John C. Bates negotiated an agreement, sometimes called the Bates Treaty for an American Sovereignty over the Moro land which still recognized and respected the position of the Sultan and the Sultanate as well as their Muslim traditions, laws, and practices with the sitting Sultan of Sulu. The treaty had little effect, however, as the Sultan had little real power. Tribal chiefs strongly resisted American control over their territories and carried out attacks against American troops and other foreigners. The treaty was unilaterally abrogated by Leonard Wood in 1905. Bates later confessed that the agreement was merely a temporary expedient to buy time until the northern forces were defeated.