The art movement of classicism
So what is Classicism? What is Neoclassicism?
Classicism is a movement that can be described by its application to traditional forms focusing on elegance and symmetry. Classicism uses the art of the Greeks and Romans as its idea of completion. Classicism developed in Rome in the late 15th century, the classical style was widespread, especially among the Renaissance artists. Their purpose was to capture the exactness of the antique age which for them symbolized the possibility of attaining absolute beauty in their art. Utilizing examples such as the ‘Belvedere Torso’ and the ‘Medici Venus’, the masters rejected emotionalism in service of attention to form and detail. Somewhat confusingly, "classicism" is often used reciprocally with the word "neoclassicism". Thus, for instance, the structural style of the US Capitol Building can be expressed either as "classicist" or "neoclassicist"; similarly, Michelangelo's Statue of David can be depicted as either an example of "classicism" or "neoclassicism".
The style’s main advocates included Michelangelo, Raphael, Correggio, and Mantegna. The classical style was revived in the late 18th and early 19th century in Neoclassicism a movement that started in response to the flamboyant Rococo style and which included artists such as Anton Raffael Mengs and Johan Joachim Winckelmann.
That said, the term "neoclassicism" is most-commonly employed to describe a specific revival of Greek and Roman art, which occurred in Europe and America between about 1750 and 1860. So while the US Capitol Building (built 1793-1829) is properly described as "neoclassicist", Michelangelo's statue is probably best described as an example of "classicism".