The Pinellas peninsula that frames the north shore of the channel past Mullet Key was, before the 1880s, very nearly empty. The man who began to change that was not a Floridian at all but a Philadelphia saw manufacturer, and the deal he struck in 1881 was, by several accounts, the largest purchase of land by a single person in the history of the world.
Hamilton Disston was born in Philadelphia in 1844, heir to Henry Disston and Sons, one of the largest saw-making firms on earth. He took over the company after his father's death in 1878, a wealthy industrialist with capital to spend and an appetite for a grand venture. He found it in Florida.
By 1881 the State of Florida was effectively bankrupt. Its Internal Improvement Fund, the body that held millions of acres of public land, was so buried in debt and lawsuits that it could not sell or develop anything; the liens froze the whole estate. Disston broke the logjam with cash. In an agreement reached in 1881 he bought four million acres outright, an area larger than Connecticut, for twenty-five cents an acre, one million dollars, and with that single stroke paid down the debt that had paralyzed the state. It was reported to be the most land ever bought by one person anywhere. The land it freed up, and the confidence the deal restored, helped touch off Florida's first great land boom and drew the railroad builders, Henry Plant and Henry Flagler, who would remake the peninsula.
Disston's interests reached directly to the water below Mullet Key. Looking for a resort town to anchor his Gulf-coast holdings, he founded Disston City on Boca Ciega Bay, the very bay the road to Fort De Soto would later cross. A hotel rose on its shore, a wharf reached out into the bay, and a Mississippi-style paddle steamer named the Mary Disston worked its waters. The town did not become the metropolis he imagined, the nearby upstart of St. Petersburg would outgrow it, but it survives today as Gulfport, and Disston's name still marks the high ground of the peninsula in places like St. Petersburg's Disston Heights. The roughly hundred and fifty thousand acres he developed on the Pinellas peninsula were the seed of its modern settlement.
His larger dream, to drain the Kissimmee valley and the northern Everglades into farmland, consumed more than a decade of dredging and only partly succeeded; he lowered Lake Okeechobee but never conquered the swamp, and after his death in 1896 the banks took most of his Florida land. Yet the failure hardly mattered to the peninsula at the bay's mouth. Disston had opened the door. The railroads, the resort towns, and the population that followed him are the reason there was eventually a city beside Tampa Bay large enough to want a park at the end of Mullet Key. He never saw Fort De Soto, and the fort was still years off when he died, but the developed, peopled shoreline that made the park possible began with his improbable, half-ruined gamble on Florida land.