What are two elements of american culture that had been borrowed from ancient roman cultures.

Two things which the American culture borrowed from ancient Roman cultures is that there are a lot of different events which are reminiscent of ancient Roman gladiator battles. While today there aren't people who're fighting for life or death, there is still the same concept present - people entertaining other people. 

Another thing is the idea that the US has to meddle into the affairs of foreign nations.  

United states v.  nixon, 418  u.s.  683 (1974),  was  a landmark  united states supreme court case  that resulted in a unanimous  decision  against president richard  nixon, ordering him to deliver tape recordings  and  other subpoenaed materials to a  federal  district  court.