He held administrative positions in Dade County,[2] moved to Tampa in 1837, and had a short stint working for the U.S. Army as a guide and courier.

[13] Cooley acquired property in Girt's Landing on the St. Marys River,[1] close to where the military units crossed East Florida that same year.

[1] Cooley later moved to Alligator Pond (near present-day Lake City), where he set up a farm and traded with the local Seminole tribe led by Chief Micanopy.

In 1820, Spanish merchant Don Fernando de la Maza Arredondo[16] began settlement of a 280,000-acre (1,130 km2) claim in the Alachua territory, which had been granted to him by King Ferdinand VII of Spain.

[1] Cooley's main occupation was gathering, processing and shipping Florida arrowroot, a starch made from the root of the coontie plant.

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.

[18][19] 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,[20] 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.

[1] At least three black slaves and several Indians cultivated sugar cane, corn, potatoes, pumpkins and other vegetables on the twenty-acre (eight-hectare) property, which also had a pen with eighty hogs.

Cooley's Key West holdings included a factory, two storage houses, kitchen and slave quarters; coconut, lime and orange trees; and domesticated and wild fowl.

As Justice of the Peace, Cooley jailed the settlers, but they were released due to insufficient evidence after a hearing at the Monroe County Court in Key West.

[1] Major Francis L. Dade, military commandant at Key West, received intelligence that Cuba and Spain were arming the Indians; investigations did not confirm the rumor.

Dade, two companies of soldiers, and all of the available arms were sent to Fort Brooke at Tampa Bay, the port designated for the commencement of the Indians' emigration.

[1] On December 28, 1835, Dade and 107 soldiers were ambushed en route from Tampa Bay to Fort King, near present-day Ocala.

[22] Six days later, Cooley led a large expedition to free the Gil Blas, a ship that had beached the previous year.

The slave had heard the Indians ascribing the massacre to an act of revenge for Cooley's having failed to obtain the conviction of Chief Alibama's murderers.

[2] Judge Marvin, a Key West justice, accused Seminole (or Calusa, depending on the source) chief Chakaika of leading the New River Settlement raiding group.

[26][27] Arriving at Key West on January 16, 1836, aboard the steamboat Champion, he was appointed temporary lighthouse keeper, staying until April of that year.

[2] Constant attacks and rumor-spreading amplified the demands of Floridian community leaders, forcing the Navy to send Lieutenant Levin M. Powell to Key West.

Lieutenant Powell built a small force of fifty seamen, ninety-five marines, and eight officers, reinforced by two schooners and the United States Revenue Cutter Washington, commanded by Captain Day.

Cooley went back to his usual duties in Indian Key (Dade County Seat); not long after, he moved to Tampa[2] but still worked occasionally as a guide.

[3] That same year, reports circulated that Cooley was spreading rumors about a Seminole chief leading a rebellion involving black slaves and Indians.

[2] Cooley befriended Captain William Bunce, a retailer striving to keep Indians in the area, as they represented a source of cheap labor.

[28] Cooley was living near the Homosassa River,[29] where the Armed Occupation Act of 1842 allowed the distribution of 160-acre (65 ha) land grants.

[30] In 1843, he was a candidate for a seat in the Florida House of Representatives for the newly created Hernando County, but he lost to James Gibbons.

[37] By 1855, Cooley had become a leader in local politics; he was the chairman at a meeting of the Democratic Party in Tampa, with sixty-five members enrolled, on August 4, 1855.

Cooley left his estate to friends, charities, a woman called Fanny Anne listed as his daughter (wife of Francis Matthews), and three grandsons and four granddaughters,[41][42] but there is no evidence that they were his blood relatives.