Following his father 's assassination , in April 1865 , Robert Lincoln moved with his mother and his brother Tad to Chicago , where Robert completed his law studies at the Old University of Chicago ( a school different from but later assumed by the university presently known by that name ) . Following his father 's assassination , in April 1865 , Robert Lincoln moved with his mother and his brother Tad to Chicago , where Robert completed his law studies at the University of Chicago ( a school different from but whose name was later assumed by the university currently known by that name ) .