Complex sentence: She remained there until sent north in June 1865, decommissioned 12 July 1865, and was sold to George Burnham, Jr., 20 July 1865 at Portsmouth, New Hampshire.
Split into simpler sentences: She remained there until sent north in June 1865. She was decommissioned 12 July 1865 and sold to George Burnham, Jr., 20 July 1865 at Portsmouth, New Hampshire.