Explanation:
Relief sculpture was introduced to the United States by Italian sculptors working on the decoration of federal government buildings during the first quarter of the nineteenth century. Exposure to this art form continued during the next several decades as American sculptors flocked to Italy, a font of artistic tradition and the primary source of inexpensive marble and labor. Thomas Crawford, William Henry Rinehart (1985.350), Edward Sheffield Bartholomew (1996.74), and other American artists built their reputations by producing idealized in-the-round statues for an international clientele while executing portrait busts for steady income. They modeled reliefs less frequently, usually focusing on ideal subjects. They looked not only to the classical past for inspiration but also to Neoclassical sculptors, especially Antonio Canova and Bertel Thorvaldsen, whose crisply treated reliefs enjoyed great esteem in both Europe and the United States
source : https://www.metmuseum.org/toah/hd/amrs/hd_amrs.htm#:~:text=Relief%20sculpture%20was%20introduced%20to,quarter%20of%20the%20nineteenth%20century.
