What long term factors led to the rise of Independence in Cuba?
Why did Cuba not become independent in the 1820's?
The decline of the Spanish Empire
It is commonly accepted that the Spanish Empire, which rose to the pinnacle of its strength under Charles V/I and Philip II was in decline by early seventeenth century and, in spite (or perhaps because?) of strenuous efforts to arrest and reverse that decline during the early 17th century, it declined and by 1643 or 1659 (not random dates..)