Many of the Exiles had fled from slavery in South Carolina and Georgia during the disruption of the American Revolutionary War (1776–1783) and then collaborated with British, and later Spanish, soldiers and traders.
Historian Anthony Dixon writes that while Caesar's personal history is somewhat obscure, "His mastery of the English language suggests either an early childhood in plantation society or rearing by slave parents.
The Indian negro, John Casar, endeavored to decoy Mr. Hunter from his house, on pretence of selling him cattle and horses.
"[5] After a 10-day siege against Edmund Gaines' troops on the Withlacoochee River, John Caesar was sent by the Seminoles to negotiate with the Americans, who had eaten all their horses to survive.
"[6] Previously a fairly cautious combatant, in line with the policies of Negro Abram and the "elderly Seminole chiefs" like Emanthla and Micanopy, in late 1836 he turned to guerrilla warfare in earnest, in response to the arrival of "zealous" American General Thomas Jesup.