Prior to planning and leading the U.S. invasion of Puerto Rico during the War of 1898, Nelson Appleton Miles had served in the U.S. Civil War (1861–65) and the Indian Wars of the 1870s and 1880s. He led campaigns against Native Americans, including those defeating Geronimo (Chiricahua Apache) and Chief Joseph (Nez Perce). After the Battle of Greasy Grass in 1876, Miles pursued the Lakota into Canada. When they returned to the U.S. in 1881 and surrendered, he captured Sitting Bull. 

As Miles sailed along the southern coast of Puerto Rico in 1898, the sight of the U.S. ships reminded of him of his experiences fighting American Indians. Later, in 1901, he recalled, “One familiar with the western plains of a quarter of a century ago might well have been reminded of a pack of large gray wolves cautiously and noiselessly moving in the shades of night, or the dim light that ushers in the dawn, upon their prey.”