The  court  in  distinguishing  between  the  taxes  which  may,  and  those
which  may  not  be  imposed  by  a  state,  say  that  a  tax  on  the  property
of  this  corporation,  as  was  the  one  under  discussion,  did  not  inter-
fere with  the  efiicienoy  of  this  governmental  agency,  while  one  upon
its  operation  would  thus  interfere  and  would  therefore  be  invalid.*;

The  principle  of  implied  exemption  from  state  taxation,  which
had  been  heretofore  applied  exclusively  to  some  species  of  financial
agency,  was  extended  to  a  very  different  kind  of  subject  matter  in
Crandall  v.  Nevada.^    A  tax  imposed  by  Nevada  upon  all  passengers

1  Railroad  Co.  v.  Peniston,  18  Wall.  5  ;  National  Bank  v.  Common-
irealth,  9  Wall.  353.
2  National  Bank  v.  Commonwealth,  9  Wall.  353.
8  Thompson  v.  Pacific  R.  R.  9  Wall.  579.
*  Railroad  Co.  v.  Peniston,  18  Wall.  5.
6  6  Wall.  35.
TAXATION  BY'  THE   STATES.  637

passing  through  and  beyond  the  boundaries  of  the  state,  was  de-
clared to  be  invalid.  The  reasons  given  by  a  majority  of  the  court
for  their  decision  were  the  following :  The  United  States  has  a  right
to  call  for  the  services  of  its  citizens  at  all  points  of  the  national
territory,  and  to  transport  its  own  troops.  Citizens  have  the  right
to  go  to  the  seat  of  government,  and  to  all  other  places  where  public
offices  are  situated,  and  to  ports  of  entry,  as  the  necessities  of  their
business  may  require.  For  these  purposes  citizens  must  travel.
