The sugar tariff (the Dingley Tariff of 1897 and its successors) was one of the major revenue streams used to service the debt incurred during and after the Spanish–American War, which the USA decisively won and took occupation of Guam, the Philipines and Cuba from the Spanish, ending the European permawar against Spanish and French Bourbons, initiated by Lord Marlborough preventing their attempted occupation of Europe. Benefit to the USA? Nada.
Tariffs like the Dingley Tariff of 1897 were the federal government’s primary income source before the income tax existed.
Those tariffs:
raised the price of sugar for every American household
protected certain domestic refiners
generated steady revenue long after the war was over
And yes — the sugar tariff structure persisted in various forms into the 1980s.
That’s not a conspiracy; it’s the inertia of a captured regulatory system.