The proposed annexation of Santo Domingo was an attempted treaty during the later Reconstruction era, with precedents under earlier administrations, but re-initiated by United States President Ulysses S. Grant in 1869, to annex Santo Domingo (as the Dominican Republic was commonly known) as a United States territory, with the promise of eventual statehood. President Grant feared some European power would take the island country in violation of the Monroe Doctrine. He privately thought annexation would be a safety valve for African Americans who were suffering persecution in the U.S., but did not include this in his official messages. Grant also believed that the acquisition of Santo Domingo would help bring about the end of slavery in Cuba and elsewhere. The proposal to annex Santo Domingo aligned with a broader US foreign policy strategy in the Reconstruction era, including pursuit of new markets in the Caribbean to absorb the increasing industrial output of American businesses. The island's raw material wealth made it an attractive prospect for the U.S. commercial interest of seeking economic expansion in the region.
In 1869, Grant commissioned his private secretary Orville E. Babcock and Rufus Ingalls to negotiate the treaty of annexation with Dominican president Buenaventura Báez. A treaty was drafted by Secretary of State Hamilton Fish that included the annexation of the country itself and the purchase of Samaná Bay for two million American dollars. Also included and supported by Grant was the provision that the Dominican Republic could apply for statehood.