Private citizens lie in honor
The Rotunda of the U.S. Capitol has been considered the most suitable place for the nation to pay final tribute to its most eminent citizens by having their remains lay in state (in the case of government officials and military officers) or in honor (in the case of private citizens).
Lying in State or in Honor | Architect of the Capitol
Only a person who has held some kind of public office can lie in state.
yesterday on the news that Rosa Parks was the first woman to "lie in honor", which is for private citizens instead of politicians, government employees.
I think RBG may be the first SC Justice to lie in in State at the Rotunda. Correction- President Taft was also on the Supreme Court.