Humboldt and Bonpland departed from La Coruña, Spain, in June 1799, on a Spanish frigate, slipping past a British blockade in the dark of night, in the midst of a storm, and carrying with him a unique document from the Spanish government. He and Bonpland had been granted complete freedom to explore -- for scientific purposes -- any or all of Spain's largely unexplored American colonies; to make astronomical observations, maps; to collect; to go wherever they wished, speak to whomever they wished. The whole arrangement was quite unprecedented (prior to this Spain had rigorously denied any such travels by foreigners), and it had come about quite by chance.
They landed [in New Granada or Venezuela], bag and baggage, on July 16, 1799. Their gear included forty-odd scientific instruments, the most versatile and finest available at the time and just the sort of thing Thomas Jefferson would have found fascinating. Included were a tiny, two-inch sextant, compasses, a microscope , barometers and thermometers that had been standardized with those of the Paris observatory before departure, three different kinds of electrometers, a device for measuring the specific gravity of seawater, telescopes, a theodolite, a Leyden jar, an instrument by which the blueness of the sky could be determined, a large and cumbersome magnetometer, and a rain gauge. Their excitement was enormous. No botanist, no naturalist or scientist of any kind, had ever been there before them. Everything was new, even the stars in the sky. "We are here in a divine country," Humboldt wrote to his brother. "What trees! Coconut trees, fifty to sixty feet high, Poinciana pulcherrima, with a foot-high bouquet of magnificent, bright-red flowers; pisang and a host of trees with enormous leaves and scented flowers, as big as the palm of a hand, of which we knew nothing ... And what colors in birds, fish, even crayfish (sky blue and yellow)! we rush around like the demented; in the first three days we were quite unable to classify anything; we pick up one object to throw it away for the next. Bonpland keeps telling me that he will go mad if the wonders do not cease soon."
Humboldt is considered to be the "second discoverer of Cuba" due to all the scientific and social research he conducted on this Spanish colony. During an initial three-month stay at Havana, his first tasks were to properly survey that city and the nearby towns of Guanabacoa, Regla and Bejucal. He befriended Cuban landowner and thinker Francisco Arrango y Parreño; together they visited the Guines area in south Havana, the valleys of Matanzas Province, and the Valley of the Sugar Mills in Trinidad. Those three areas were, at the time, the first frontier of sugar production in the island. During those trips, Humboldt collected statistical information on Cuba's population, production, technology and trade, and with Arrango, made suggestions for enhancing them. He predicted that the agricultural and commercial potential of Cuba was huge and could be vastly improved with proper leadership in the future. After traveling to America, Humboldt returned to Cuba for a second, shorter stay in April 1804. During this time he socialized with his scientific and landowner friends, conducted mineralogical surveys and finished his vast collection of the island's flora and fauna.