 Cooley's main occupation was gathering, processing and shipping arrowroot, a starch made from the root of the coontie plant. Arrowroot was used to make bread dough, wafers and biscuits; its resistance to spoilage made it especially favored for use on ships. Pulp remaining after processing was used as a fertilizer or for animal rations. Favorable conditions for arrowroot cultivation contributed to the presence of several hundred Indians in the area — arrowroot being a staple of their diet. The market price for the starch was between 8 ¢ (US) and 16 ¢ per pound (between 17 ¢ and 35 ¢ per kg), and the geography of the river and the good performance of his machinery — the output was close to 450 lb (200 kg) per day — brought Cooley great prosperity. His good fortune allowed him to dedicate much of his time to exploration of the area as far north as Lake Okeechobee and brought him increasing political influence. It is likely that he married Nancy Dayton, a former Indian captive, on December 2, 1830. Richard Fitzpatrick, by that time the owner of a successful plantation with coconut and lime trees, plantains, and sugarcane, pressed for the appointment of Cooley as Justice of the Peace in 1831, making Cooley responsible for adjudicating disputes of persons and property, punishment of minor offenders by fines and whippings, and oversight of the activities of wreckers. Serious offenders were jailed in Key West. By that time, Cooley owned a schooner and took trips not only to take prisoners but to trade coontie, sugarcane, and tropical fruit with Cape Florida, Indian Key, Key West and Havana.
