Building height: 1,362 feet, the height of the original WTC South Tower.
Building, with observation deck, height: 1,368 feet, the height of the original WTC North Tower.
Building, with observation deck and antenna, height: 1,776 feet, the year the Declaration of Independence was signed.
Base: 200 feet square, the same as the original twin towers.
July 2002 - The first round of designs for a new WTC site are put on display for public comment. The public rejects the designs as being uninspired and all are scrapped.
August 2002 - The LMDC invites architects from around the world to submit ideas for the World Trade Center site.
December 2002 - Semifinalists in the second round of the design contest exhibit their work at the Winter Garden in the World Financial Center.
February 2003 - Architect Daniel Libeskind's "Memory Foundations" is selected as the new design plan for the World Trade Center site.
July 2003 - Architect David Childs, of Skidmore, Owings & Merrill, is selected to design Freedom Tower, which will be the tallest of the four towers planned for the WTC site.
December 19, 2003 - Plans for Freedom Tower are revealed. The skyscraper will occupy the northwest corner of ground zero.
July 4, 2004 - During a special ceremony, a 20-ton slab of granite, inscribed "the enduring spirit of freedom" is laid as the cornerstone of Freedom Tower by Mayor Michael Bloomberg.
May 4, 2005 - New York Governor George Pataki announces that Freedom Tower will be redesigned due to security concerns.
June 29, 2005 - The revised plans for Freedom Tower are released.
April 26, 2006 - The Port Authority of New York and New Jersey and developer Larry Silverstein reach an agreement about the financing of Freedom Tower, resolving problems that had delayed construction at the site.
April 27, 2006 - Construction begins on Freedom Tower.
March 26, 2009 - The Port Authority of New York and New Jersey announce that going forward the skyscraper will no longer be referred to as Freedom Tower. It will be called by its legal name and address, One World Trade Center.
May 10, 2013 - Construction workers bolt the last pieces of a 408-foot spire into place atop One World Trade Center, bringing the building to a height of 1,776 feet.
November 12, 2013 - The Council on Tall Buildings and Urban Habitat announce that upon completion One World Trade Center will officially be the tallest building in the Western Hemisphere and the third-tallest in the world. There had been some concern as to whether a 408-foot needle atop the One World Trade Center would be counted in the total height of the tower.
March 2014 - In two separate incidents, trespassers are arrested for sneaking into the building and climbing to the top. The first episode involves a New Jersey teen who accessed the site via a hole in the fence. Days later, a group of four stunt jumpers climb to the upper floors and parachute to the ground.
November 3, 2014 - One World Trade Center opens when the first tenant, Conde Nast, moves in.
November 12, 2014 - Two window washers are rescued by emergency workers outside the 68th floor of the building after a cable comes loose from their suspended platform. The crews cut through thick glass to get the men off the damaged platform.
May 29, 2015 - The One World Observatory opens in three upper floors of the tower. The complex loops around 360 degrees, with views of New York and New Jersey from about 1,250 feet up in the air. In addition to the main observatory, the complex features three restaurants, an exhibit called Voices about the construction of One World Trade Center and an area called the Sky Portal, a circular platform with a live video feed of ground-level street scenes.