What was one of lincoln's hidden weapons in the civil war?

It was railroads because it was private then later became government ownership.

Idkk take a guess i am no

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.