Simplify the following text for a Grade 11 native English-speaking person.
Original: Temporary buildings built in 1866 for the Intercolonial Exhibition remained in use by the library until 1909 , when work began on a new annexe building to mark the library 's Jubilee .
Simplified: Temporary buildings built in 1866 for the Intercolonial Exhibition were used until 1909 , when work began on a new building to mark the library 's Jubilee .