Everglades (n.) Look up Everglades at Dictionary.com
1823, from everglade, from ever, perhaps in sense of "endless" + glade.
The distance from the mouth of Hilsborough river to the head of the lake, in a direct line, is about 110 statute miles. The country between them is mostly, if not wholly, an everglade, by which is meant a low marsh frequently covered with water, and in which there grows a sharp triangular grass, from ten to twelve feet high, and impervious to men or animals. ["American Mechanics' Magazine," 1825]