Probable answer that you're seeking: Napoleon's conquest of Spain led to independence movements in the Americas.
Further detail:
Napoleon's focus was set on gaining dominance over the whole of Europe. Maintaining control of lands in the Americas was not as vital to him. Note, for instance, that it was also during the administration of Napoleon in France that great amounts of French lands in North America were sold to the United States in what was known as "The Louisiana Purchase."
As far as Spanish-held lands in the Americas, Napoleon's takeover of Spain caused less commitment to be given to holding on to those territories. Maintaining control of Spain itself was difficult enough for Napoleon's regime. (Guerilla warfare in Spain continued to challenge French occupation there.) Plus there was a mood of revolution and the rights of citizens in the air, which had been spawned by the French Revolution that had brought Napoleon himself to power. So during the ensuing years, after Napoleon established his control in France and fought wars in Europe, independence movements broke out across Latin America. There were a number of key leaders of such movements, such as Simón Bolivar
, active in independence efforts in his own country, Venezuela, as well as Bolivia (a country which was named after him for his role in its independence), plus Colombia, Ecuador and Peru. Bernardo O'Higgins was instrumental in independence efforts in Chile, which achieved independence in 1817. José de San Martín was active as a liberator for his native Argentina in 1810, as well as movements in Chile and Peru.
