Jules Verne
Along with H. G. Wells, Verne is generally thought of as one of the founding fathers of SF. However, neither of them claimed this honour nor bestowed it upon the other, nor did they ever claim to starting a new genre.
Rebelling against his father's desire for him to follow him as a lawyer, and his love of adventure, Jules attempted to swap places with a cabin boy and was discovered only after the ship left the harbour.
His first story of SF interest, Un Voyage en Balloon, 1851, came after his reading of E. A. Poe. The tale was later republished in, Une Fantaisie du Docteur Ox, 1872. In the UK translated as Dr Ox's Experiment, and Other Stories, 1874, and in USA as Doctor Ox and Other Stories, 1874
With, Paris in the 20th Century, Verne took his first, and only, trip into future earth. Set in a Dystopian corporate dictatorship in Paris in 1960, the story is noteworthy for its predictions; 1960 Paris had cars, pneumatic tube-trains, computers and faxes.
His next novel, Journey to the Centre of the Earth, 1863; 1872, UK, abandons futurity and steps straight into a typical 19th century adventure that is also touching on SF, the hollow Earth, without actually tripping over the edge and falling into the unknown.
The next decade saw the emergence of, perhaps, his most well known stories: From the Earth to the Moon in 97 hours 20 minutes, and a Trip Around It, 1873 UK; Twenty Thousand Leagues under the Seas; The Mysterious Island; and, Around the World in Eighty Days.