Second Ladies and Gentlemen of the United States

The second lady of the United States or second gentleman of the United States (SLOTUS or SGOTUS), is the informal title held by hostess of the Number One Observatory Circle, usually the wife or husband of the vice president of the United States, during the vice president's term in office. 
Doug Emhoff is the current second gentleman of the United States, in role since January 2021 as the husband of Vice President Kamala Harris.
Twelve women went on and became become first lady of the United States following their husbands becoming the president of the United States, the first woman was Abigail Adams and the most recent woman is Jill Biden.
Origins and Role.
The second lady or gentleman is not elected by the people of the United States. There are no official jobs he or she is officially required to perform and they are not paid for being the second spouse, but they are often involved in political campaigns, managements of the Number One Observatory Circle, participating in social causes and representing the vice president at official and ceremonial occasions and accompanying the vice president on foreign summits and events.
List of second ladies and gentlemen of the United States.
Abigail Adams · Ann Gerry · Hannah Minthorne Tompkins · Floride Calhoun · Letitia Christian Tyler · Sophia Dallas · Abigail Fillmore · Mary Cyrene Burch Breckinridge · Ellen Vesta Emery Hamlin · Eliza Johnson · Ellen Maria Colfax · Eliza Hendricks · Anna Morton · Letitia Stevenson · Jennie Tuttle Hobart · Edith Roosevelt · Cornelia Cole Fairbanks · Carrie Babcock Sherman · Lois Irene Marshall · Grace Coolidge · Caro Dawes · Mariette Rheiner Garner · Ilo Wallace · Bess Truman · Jane Hadley Barkley · Pat Nixon · Lady Bird Johnson · Muriel Humphrey Brown · Judy Agnew · Betty Ford · Happy Rockefeller · Joan Mondale · Barbara Bush · Marilyn Quayle · Tipper Gore · Lynne Cheney · Jill Biden · Karen Pence · Doug Emhoff
List of living former second ladies of the United States.
As of 2023, there are only five living former second ladies.