From Wiki:
Because the assembly fell behind schedule, the piece was
temporarily uncovered for the opening of Millennium Park in July
2004. The public appreciation for the piece convinced park
officials to leave it open for public view for several months. The
piece was then re-tented for over a year to allow the seams between
its metal plates to be polished out. The sculpture was finally
completed and dedicated on May 15, 2006.
