I think your talking about Neoclassical architecture. When ancient Roman citites were discovered such as Herculaneum and Pompeii, artist wanted to replay the ideal picture of classical Greece and Rome in their architecture. So the artists and architects used Neoclassicism from Europe for aesthetic and even political reasons. They used Neoclassicism in the entire 18th century for buildings, paintings, etc..
What eighteenth century American architecture shows widespread influence?
- University of Virginia
- White House ( United States Capitol building )
- Columbia University
Hope this helps :)