Man from Atlantis is a short-lived American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 television series that ran for 13 episodes on the NBC Network

NBC

The National Broadcasting Company is an American commercial broadcasting television network and former radio network headquartered in the GE Building in New York City's Rockefeller Center with additional major offices near Los Angeles and in Chicago...

 during the 1977–1978 season, following four successful television movie

Television movie

A television film is a feature film that is a television program produced for and originally distributed by a television network, in contrast to...

s that had aired earlier in 1977.

NBC commissioned four movies for the show during the 1976–1977 season. Ratings success by these movies led to the commissioning of a weekly series for the 1977–1978 season.
The series stars Patrick Duffy as an amnesia

Amnesia

Amnesia is a condition in which one's memory is lost. The causes of amnesia have traditionally been divided into categories. Memory appears to be stored in several parts of the limbic system of the brain, and any condition that interferes with the function of this system can cause amnesia...

c man given the name of Mark Harris, believed to be the only surviving citizen of the lost civilization of Atlantis

Atlantis

Atlantis is a legendary island first mentioned in Plato's dialogues Timaeus and Critias, written about 360 BC....

.