Summerlin was a highly successful cattleman utilizing his own sweat and brow up and down Florida, shipping cattle off to Cuba for most of his life.
Wild cattle brought to North America by the Spanish conquistadors roamed free across these vast stretches of land.
Summerlin and his business partners developed a lucrative trade with Havana and with the US Naval Base at Key West.
[2] However, after the break out of the American Civil War, Jacob was quoted in official USA documents that he never killed any person.
He was a generous hard working American cattleman, feeding soldiers in the civil war as was ordered by both Confederate and Union armies.
Separately and privately, he still sailed past the Union blockade mostly at night to continue cattle sales to Cuba as usual.
But, with hard work and Union money that he earned, Jacob bought the 160-acre (0.65 km²) Blount homestead, much of which would later be given to Polk County.
Summerlin amassed a fortune of 15,000 to 20,000 head of cattle during this period and was considered one of the wealthiest Floridians before he reached age 40.
In this pre-banking era, Jacob kept his gold and silver at his cabin in trunks, meal sacks, tin meat cans, woolen socks, cigar boxes, behind door frames, in the rafters, or tossed in a corner.
He bought a wharf at Punta Rassa and a thousand acres (4 km²) nearby for cow pens, some of which he rented to other cattlemen.