After years of stalled development, steel at the building reached the 52nd story on Thursday, more than 600 feet above ground.
The tower is slated to stand at 104 stories, with an antenna reaching hundreds of feet higher, bringing it to a symbolic 1,776 feet - the tallest in the country.
The building was renamed to better attract corporate tenants, but the Freedom Tower name has stuck for many and still remains on the Lower Manhattan Development Corporation's website detailing the rebuilding.
On Thursday, a worker wearing a hard hat drove a bolt into a steel column on the 52nd floor. It takes so long for workers at the rising tower to return to the ground that a Subway sandwich shop built out of shipping containers is being raised along with the building by a hydraulically powered platform.
The skyscraper is one of several envisioned at the site, along with a Sept. 11 memorial, transit hub and performing arts center.
The memorial, with reflecting pools set above the footprints of the fallen towers, is expected to open by the 10th anniversary of the 2001 attacks.