1939 World's Fair,
Flushing, NY

"World trade center" pavilion is dedicated to "world peace through trade."


Downtown Lower Manhattan Association is created by real estate developer David Rockefeller to revitalize lower Manhattan and begins to promote the idea of a "world trade and finance center" in New York City.

January 1960

David Rockefeller presents a plan for a world trade center along the East River of Manhattan. The Port of New York Authority is commissioned to study the plan.  

March 1961

On March 10, Port Authority issues a favorable report on the feasibility of developing a world trade center.

February 1962

New York and New Jersey authorize the development of the World Trade Center.

December 1962

World Trade Center location moves to West Side amidst protests by displaced business owners.

November 1963

The Port Authority wins legal challenge to the development of the WTC. 

January 1964

The Port Authority unveils an architectural plan for the WTC featuring the world’s tallest buildings.

March 1966

Construction begins on March 21 at the WTC site with the demolition of 78 Dey Street.

August 1966

Excavation work begins for the WTC.  First use of "slurry wall" method in the United States.

June 1967

New York City Board of Estimates formally approves the WTC legislation.

October 1970

The North Tower of the WTC exceeds the height of Empire State Building, making it the tallest building in the world. 

December 1970

The first tenants move into North Tower of the WTC on December 15. 

December 1970

The North Tower of the WTC is topped off at 1,368 feet on December 23.

July 1971

The South Tower of the WTC is topped off at 1,362 feet on July 19.

September 1971

The first tenant moves into Two World Trade Center (South Tower).

March 1972

The first tenant moves into Five World Trade Center (Northeast Plaza Building).

April 1973

The World Trade Center is dedicated on April 4.

January 1974

U.S. Customs Service moves into Six World Trade Center.

August 1974

Tightrope artist Phillippe Petit performs an unauthorized walk between the Twin Towers on April 7. 

December 1975

Top of the World Observation Deck opens at Two World Trade Center (South Tower).

April 1976

The Windows of the World Restaurant opens at the top of the North Tower on April 19.

January 1977

The first tenant moves into Four World Trade Center (The Commodities Exchange Center).

May 1979

The 360-foot spire atop One World Trade Center is completed.

July 1981

The Vista International Hotel, the first hotel built in Lower Manhattan since 1836, opens.

May 1987

Seven World Trade Center opens.

February 1993

On February 26, terrorists detonate 1,500 pounds of explosives in a van parked in the underground public parking lot of the WTC, two levels below the southern wall of the North Tower. The attack kills six people, including a pregnant woman, injures more than 1,000 people and creates a five-story crater beneath the towers, resulting in hundreds of millions of dollars of damage.

March 1993

The WTC reopens for business on March 19, led by tenant New York Governor Mario Cuomo and his staff.  The Port Authority implements a $250 million upgrade plan focusing on life safety and security.   


The WTC is designated one of the "Seven Wonders of the Modern World" by the American Society of Civil Engineers. The WTC is visited by every U.S. president between the time of its opening and the time of its destruction at least once, as well as by many dignitaries and heads of state.

Spring 1995

A memorial fountain is dedicated in the WTC plaza to the victims of the 1993 bombing. 

December 1995

The Vista International Hotel is sold and renamed the New York Marriott World Trade Center Hotel.

September 1998

On September 24, The Port Authority announces plans to seek a 99-year net lease of the complex.


The WTC reaches its highest occupancy rate. 

July 2001

The WTC is net-leased on July 24 to private developer Silverstein Properties, Inc. for approximately $3.2 billion. A three-to-six month transition period commences. 

September 11, 2001

Two planes hijacked by terrorists crash into the Twin Towers, destroying the complex. One World Trade Center is struck at 8:46 a.m.; Two World Trade Center at 9:03 a.m..  To read the timeline of events of that day including two other associated terrorist hijackings, please click here.

September 12, 2001
12:30 PM

Last survivor is rescued from the WTC site at approximately on 12:30 p.m.

September 14, 2001

National Day of Prayer and Remembrance; President Bush visits Ground Zero.

September 17, 2001

New York Stock Exchange reopens.

September 23, 2001

Prayer for America service takes place at Yankee Stadium.

October 17, 2001

Robin Relief Fund holds a concert for first responders at Madison Square Garden.

October 28, 2001

An interfaith ceremony is held at the WTC site.

March 11, 2002

Six-month anniversary of the September 11 attacks is marked with beams of light.

May 30, 2002

The WTC recovery ends with a public Last Column Ceremony.


The 9-11 Commission is created to study the events leading up to the September 11 attacks and to provide recommendations on emergency preparedness and response. The 9-11 Commission issues its report on July 22, 2004. 


A study by the Center for Disease Control reports that the majority of 9-11 survivors continue to suffer from psychological trauma.  A May 2006 study prepared for the American Red Cross reports that the majority of people who received therapy after the attacks are still suffering.  

May 2006

The newly constructed 7 World Trade Center opens on May 23, the first building to be rebuilt in Lower Manhattan after the September 11 attacks.

Rebuilding the World Trade Center Site

December 2001

A program to restore Port Authority Trans-Hudson (PATH) rapid-transit rail service disrupted by the September 11 terrorist attacks is approved. Planning also is authorized for a permanent World Trade Center PATH Terminal and redevelopment of the World Trade Center site.

February 2002

Work begins at Exchange Place Station in Jersey City, to repair damage and enable restoration of PATH service to the Jersey City waterfront. The Port Authority begins outlining concepts for a downtown transportation hub linking PATH, subway lines, ferry service and areas adjoining the WTC site.

July 2002

Following completion of emergency activities, responsibility and control of the World Trade Center site is transferred from New York City to The Port Authority. The Port Authority begins work on the temporary World Trade Center PATH station.

August 2002

New York Governor George Pataki and New Jersey Governor James McGreevey dedicate a World Trade Center site viewing fence with heroes’ names and other information panels. The first steel column is erected at the WTC site for the temporary PATH station.

November 2002

A groundbreaking ceremony is held for 7 WTC and the Con Ed substation.

February 2003

The Port Authority and the Lower Manhattan Development Corporation (LMDC) announce the selection of Memory Foundations by Studio Daniel Libeskind as the design concept for The World Trade Center site.

June 2003

PATH service resumes at the Exchange Place Station in Jersey City, NJ on June 29, restoring a critical link in trans-Hudson PATH service and creating greater access to expanded ferry service to Lower Manhattan.

July 2003

The LMDC begins the public environmental review process for the WTC Memorial Redevelopment Plan. The Port Authority announces the selection of Downtown Design Partnership and the internationally renowned architect Santiago Calatrava to perform preliminary engineering and architectural services for the design and construction of The World Trade Center Transportation Hub.

September 2003

A refined WTC Site Master Plan is presented.

October 2003

The Port Authority conducts public meetings for environmental review of The World Trade Center Transportation Hub.

November 2003

The temporary WTC PATH Station opens on November 23, ahead of schedule, reconnecting lower Manhattan and New Jersey.

December 2003

Design concept for The World Trade Center site’s 1,776-foot One World Trade Center is unveiled on December 19.

January 2004

Architects Michael Arad and Peter Walker present the winning design concept for The World Trade Center Memorial. Santiago Calatrava presents design concepts for The World Trade Center Transportation Hub.

July 2004

Ground breaking for the One World Trade Center takes place.

December 2004

Final design of the WTC Memorial and museum is unveiled.

May 2005

Design is unveiled for The World Trade Center Cultural Center by Snøhetta.

June 2005

A revised design for the One World Trade Center is released with unprecedented life safety and security features.

July 2005

The Port Authority Board of Commissioners authorizes the $2.221 billion World Trade Center Transportation Hub project. Architect Santiago Calatrava presents his refined design.

July 2005

The Federal Transit Administration and The Port Authority announce $699 million of additional federal funding for WTC infrastructure work, and $478 million for a new World Trade Center Vehicle Security Center project.

September 2005

Construction begins on the World Trade Center Transportation Hub on September 6.

March 2006

Preliminary construction work begins on The World Trade Center Memorial on March 13.

April 2006

The Port Authority Board of Commissioners approves the framework proposal for a new lease agreement with World Trade Center developer Larry Silverstein on April 27. Under the framework proposal, Silverstein Properties continues to build Towers 2, 3 and 4. Silverstein Properties surrenders its lease rights for the One World Trade Center and Tower 5 to The Port Authority.

April 2006

Construction officially begins on the One World Trade Center on April 28.

May 2006

Seven World Trade Center opens on May 23.

July 2006

The Port Authority assumes responsibility for construction of the World Trade Center Memorial.

August 2006

Preliminary work begins on east/west concourse for World Trade Center Transportation Hub. Construction of The World Trade Center Memorial resumes.

September 2006

The Port Authority finalizes agreements on September 21, giving The Port Authority control of construction of the One World Trade Center and Tower 5. Architectural designs for Towers 2, 3, and 4 are unveiled.

June 2007

On June 21, the Board of Commissioners authorizes The Port Authority to enter into a long-term sub-net lease with JPMorgan Chase & Co. to develop Tower 5 as a 1.3 million-square-foot skyscraper at The World Trade Center site.

February 2008

Tower 3 and 4 site turned over to Silverstein Properties.

March 2008

PATH Temporary North Access Station opens.

September 2008

First Installation of Memorial Steel.




WTC site layout

View Construction Photos