user: Question: What is the primary conference that was founded before 1866 and has an affiliation of Private/Catholic?
Columns: ['School', 'Location', 'Founded', 'Affiliation', 'Enrollment', 'Nickname', 'Primary conference']
Types: ['text', 'text', 'real', 'text', 'real', 'text', 'text']
Sample row: ['Drexel University', 'Philadelphia, PA', 1891.0, 'Private/Non-sectarian', 17000.0, 'Dragons', 'Colonial Athletic Association ( D-I )']
SQL:

assistant: SELECT "Primary conference" FROM "Table" WHERE "Founded" < 1866.0 AND "Affiliation" = 'Private/Catholic';