Watch and Wait by Oliver Optic

The place where the Isabel had been moored was in the midst of a gloomy and extensive swamp. Though Dan had never been here before, he had heard of the region, and from the first had determined to conceal his party within its deep and almost impenetrable morasses. The swamp was about fifteen miles in extent from north to south, and ten from east to west. It was full of bayous and lagoons, and inhabited only by herons, alligators, and other wild animals of the south-west.

It was impossible to penetrate the swamp without a boat, for the _terra firma_ of the region consisted only of islands covered with trees, most of them surrounded by shallow and muddy waters. It is doubtful whether any human being had ever fully explored this extensive swamp; and Dan was confident that, if he could succeed in making his way with the Isabel to a distance of two or three miles from the lake, his party would be free from intrusion, unless, indeed, the slave-hunters made a business of driving them from their covert.