Complex sentence: For a time it was a museum and then was used as a residence by Choate Rosemary Hall, until donated to the Wallingford Historic Preservation Trust in 1999.
Split into simpler sentences: For a time it was a museum and then was used as a residence by Choate Rosemary Hall, until donated to the Wallingford Historic Preservation Trust. The house was donated by Choate Rosemary Hall to the Wallingford Historic Preservation Trust in 1999.