Table: us_house_successors
Columns: district
vacator
reason_for_change
successor
date_successor_seated

Question: On what date was James P. Buchanan (d)'s successor seated?
SQL: SELECT "date_successor_seated" FROM us_house_successors WHERE "vacator" = 'James P. Buchanan (D)'

Question: How many people vacated to successor Dave E. Satterfield, Jr. (d)?
SQL: SELECT COUNT("vacator") FROM us_house_successors WHERE "successor" = 'Dave E. Satterfield, Jr. (D)'

Question: Why did Robert L. Bacon (r) vacate?
SQL: SELECT "reason_for_change" FROM us_house_successors WHERE "vacator" = 'Robert L. Bacon (R)'