This Commemorative arch by Olin L. Warner (1844-1896) leading to the Main Reading Room commemorates the erection of the Library of Congress. Its sculpture The Students represents the pursuit of knowledge. On the left a young man seeks knowledge through reading. On the right an older man with flowing beard is shown absorbed in meditation, no longer concerned so much with a source of learning because he observes life and engages in original reflection and thought.
In the frieze above them the words -Library of Congress,- are inscribed in tall gilt letters.
The above is from https://www.loc.gov/visit/tours/online-tours/thomas-jefferson-building/great-hall/