On December 23rd, 1970, the last bit of steel was placed on top of the North Tower of One World Trade Center. This piece of steel completed the tower at 1353 feet tall, the tallest building in the world for three years before the completion of the Willis (formerly Sears) tower in 1973.

WTC 1 was in fact declared the tallest building in the world that October, before construction was completed. At that time, the building stood at 102 stories high and 1254 feet above street level. It surpassed the Empire State Building by four feet. See the news, reported by the New York Timeshere

Following suit, Two World Trade Center—the South Tower—was completed in July of 1971. However, construction of the World Trade Center complex wasn’t finished until 1973, after the completion of the five acre outdoor plaza.

Construction on the World Trade Center began in the February of 1967. In order to make room for the towers, the construction company had to raze “Radio Row”, a strip of mom and pop stores known as the hub of the electronics industry in the 1950s between Liberty, Church, West, and Barclay Streets. The construction of the World Trade Center also radically changed the Manhattan shoreline, which we detailed in this series of maps previously.

For more on the current construction of a new World Trade Center, check out our photos from its see-through floor, and our description of how it will be the tallest building in the United States after completion.