Atlantis is an alternate history series by Harry Turtledove, in which the east coast of North America split off from the rest of the continent around 85 million years ago and formed Atlantis, a separate continent farther east in the Atlantic.
In the preface to "Audubon in Atlantis" published as part of the collection Atlantis and Other Places, Turtledove mentions that his inspiration was reading that New Zealand had separated from Australia some 85 million years ago and wondering about the implications if the same thing had happened to a large chunk of eastern North America.
- "Audubon in Atlantis", the first-published story in the series, set in 1843, focusing on John James Audubon's expedition to the continent/country of Atlantis. It takes place between The United States of Atlantis and Liberating Atlantis
- "The Scarlet Band", a Sherlock Holmes pastiche set decades after Audubon's trip, focusing on a controversial religious movement called the House of Universal Devotion. Chronologically it is the last story set in this world.
- Opening Atlantis, chronologically the first in the series, detailing the discovery of the continent by Europeans in 1452, its settlement, and its role in the conflict between Great Britain and France in the mid-18th century.
- The United States of Atlantis, the second novel, detailing the Atlantean War of Independence, and the creation of the new country, the United States of Atlantis.
- Liberating Atlantis, the third novel, which depicts the Atlantean Servile Insurrection.