Table: successors_1941
Columns: district
vacator
reason_for_change
successor
date_successor_seated

Question: Name the vacator for wisconsin 1st
SQL: SELECT "vacator" FROM successors_1941 WHERE "district" = 'Wisconsin 1st'

Question: Name the successor for pennsylvania 15th
SQL: SELECT "successor" FROM successors_1941 WHERE "district" = 'Pennsylvania 15th'