user: Question: When did the elections take place in district Maryland 2?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Results', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Maryland 1', 'Wayne Gilchrest', 'Republican', 1990.0, 'Re-elected', 'Wayne Gilchrest (R) 69% Irving Pinder (D) 31%']
SQL:

assistant: SELECT "First elected" FROM "Table" WHERE "District" = 'Maryland 2';