First family is an unofficial title for the family of a republic's head of state. A first family usually consists of: the head of state, the first spouse and their children.
The term second family is often used to refer to the deputy head of state, usually a vice-president, or, in some countries, the family of the prime minister, in deference to a first family or royal family. The spouse is called the second lady or second gentleman.
The use of the term "first family" to refer to the family of the President of the United States only came into widespread use during the Kennedy administration with the tremendous popularity of Vaughn Meader's 1962 comedy album, The First Family.[1]
The First Family is also a collection of Australopithecus afarensis fossils discovered at site "333" at Hadar in Ethiopia, near the location of another famous A. afarensis, Lucy. A. afarensis is believed to be the first habitual bipedal hominid and a direct ancestor of Homo sapiens. This species lived between 3.9 million to 2.9 million years ago.