Although local belief was that it had been a Spanish structure, it is now presumed to date from the Glades archaeological culture, which lasted from about 500 BCE until shortly after the arrival of Europeans in Florida.

[3] Archaeologists place the Florida Keys in the Tekesta or Everglades region of the Glades archaeological culture area.

[6] The island was called Cayo de la Leña (Spanish for "Isle of Wood") on a chart in 1760.

In the 1830s, residents of nearby Indian Key, who called the island "Lignurd Vitoz", grew crops, including sisal, on it.

[7] Records of the ownership of Lignumvitae Key go back to 1843, including the years of 1919-1953 when the Matheson family of Miami owned the island.