 General Thomas Jesup , headquartered in Fort Dade , made Cooley an express rider in early 1837 to deliver messages between Tampa Bay and Fort Heilman , a corridor of 170 miles ( 270 km ) . That same year , reports circulated that Cooley was spreading rumors about a Seminole chief leading a rebellion involving black slaves and Indians . Afraid that Cooley could be directly involved , the general had him interrogated . Afterwards , a disgusted Cooley resigned his position . 
