“From 1812 to 1818, the blacks among the tribespeople had been recognized for their military prowess and aggressiveness. But after 1821, when they were more closely scrutinized, their intellect and the power they wielded over their Seminole ‘lords’ were now emphasized. One observer said: ‘The negroes, who dwell among these people as slaves, are intelligent, speak the English language, … and … have great influence over … the Indians.
… They fear being again made slaves, under the American government, and will omit nothing to increase or keep alive mistrust among the Indians, whom they in fact govern. If it should be necessary to use force with them, it is to be feared the Indians would take their part. It will, however, be necessary to remove from the Floridas this group of lawless freebooters, among whom runaway negroes will always find refuge.'”
Sources: The Black Seminoles: History of a Freedom Seeking People by Kenneth W. Porter, Revised and Edited by Alcione M. Amos and Thomas P. Senter University Press of Florida, 1996, p. 27; and Morse, Jedidiah.  A Report of the Secretary of War of the United States on Indian Affairs. St. Clair Shores, Mich.: Scholarly Press, 1972 pages 310-311