Short answers, pulled from the story.
Adventure fiction is defined by protagonists living in constant danger of imprisonment or death rather than by its setting. This specific definition of danger as the core engine of the genre separates true adventure fiction from stories that merely contain a single exciting scene.
The American pulp magazine era dominated popular fiction between the Progressive Era and the 1950s. Magazines such as Adventure, Argosy, Blue Book, Top-Notch, and Short Stories specialized in this genre during this period.
Johann David Wyss wrote The Swiss Family Robinson as an early and enduring example of adventure fiction for children. Victorian era writers W. H. G. Kingston, R. M. Ballantyne, and G. A. Henty specialized in the production of adventure fiction for boys.
Sir Walter Scott and Alexandre Dumas, père laid the groundwork for historical adventure. Later writers like Jules Verne and Rudyard Kipling pushed the boundaries of imagination and geography.
Adventure fiction often overlaps with war novels, crime novels, detective novels, sea stories, and spy stories. Science fiction and fantasy have also been deeply intertwined with adventure, as seen in the works of Robert E. Howard and J. R. R. Tolkien.