Mather  was  elected  to  the  lower  branch  of  the
Second  General  Assembly  from  Randolph
County,  was  re-elected  to  the  Third  (serving  for
a  part  of  the  session  as  Speaker),  and  again  to  the
Fourth,  but,  before  the  expiration  of  his  last  term,
resigned  to  accept  an  appointment  from  Presi-
dent John  Quincy  Adams  as  Commissioner  to
locate  the  military  road  from  Independence  to
Santa  Fe,  and  to  conclude  treaties  with  the
Indians  along  the  line.  In  the  Legislature  of
1822  he  was  one  of  the  most  determined  oppo-
nents of  the  scheme  for  securing  a  pro-slavery
Constitution.  In  1828  he  was  again  elected  to
the  House  and,  in  1832,  to  the  Senate  for  a  term
or  four  years.  He  also  served  as  Colonel  on  the
staff  of  Governor  Coles,  and  was  supported  for  the
United  States  Senate,  to  fill  the  vacancy  caused
by  the  death  of  John  McLean,  in  1830.  Having
removed  to  Springfield  in  1835,  he  became  promi-
nent in  business  affairs  there  in  connection  with
his  former  partner,  Mr.  James  L.  Lamb;  in  1837
was  appointed  a  member  of  the  first  Board  of
Fund  Commissioners  for  the  State  under  the
internal  improvement  system ;  also  served  seven
years  as  President  of  the  Springfield  branch  of
the    State    Bank ;    was    connected,  as    a    stock-


holder, with  the  construction  of  the  Sangamon  &
Morgan  (now  Wabash)  Railroad,  extending  from
Springfield  to  the  Illinois  river  at  Naples,  and
was  also  identified,  financially,  with  the  old  Chi-
cago &  Galena  Union  Railroad.  From  1835  until
his  death,  Colonel  Mather  served  as  one  of  the
Trustees  of  Illinois  College  at  Jacksonville,  and
was  a  liberal  contributor  to  the  endowment  of
that  institution.  His  death  occurred  during  a
visit  to  Philadelphia,  March  28,  1853.
