Skyscrapers have come to define our cities.
But the vertical urban landscapes we are familiar
with today were in fact enabled by an engineering and construction rivalry between two of America’s
largest cities, that stretches back almost 130 years.
Up until the 19th century, tall buildings were largely limited to military fortifications,
bell towers and religious structures - that used their height for strategic, ornamental
or spiritual purposes.
With land more freely available and stairs as the only means of vertical access, there
was little to drive the construction of high rise structures.
Additionally, the practice of building with external load-bearing walls caused structures
to thicken at their bases as they grew taller,
reducing floor area on the more desirable lower levels.
The industrial revolution drove significant growth in urban areas and introduced new innovations
into the construction industry.
In the midst of a booming recovery from the Great Fire of 1871, availability of land in
the city of Chicago forced developers and engineers to embrace these new innovations
and to begin building upwards.
The result was the Home Insurance Building - a 10 storey structure completed in the late
1880s that became the world’s first skyscraper.
The building was the first tall structure to be supported both internally and externally
by a fireproof metal frame.
Engineer architect William Le Baron Jenney, hung lightweight masonry walls from the steel
structure, reducing its weight by two thirds as compared to an equivalent stone building.
He also incorporated a hydraulic elevator, greatly improving vertical access.
Seen as a modern wonder, the principle employed at the Home Insurance Building quickly became
a favoured design technique in Chicago.
By 1893, the city was home to 12 buildings that stood between 16 and 20 storeys tall
- including the 302 foot (92 metre) Masonic Temple, which, upon the removal of the Board
of Trades clock tower, was the tallest building in the city between 1895 and 1899.
Fighting for dominance with European markets and experiencing a tripling of its population
between 1840 and 1870, New York City saw Chicago’s vertical progress as a solution to the challenges
it faced.
New York City’s planning authorities approved the use of metal frames in 1889 and allowed
the 11 storey Tower Building to be built - paving the way for numerous other high rise structures
across city, though notably more modest in height than those found in Chicago.
As America’s cities continued to boom at the end of the 19th century, it seemed that
Chicago was destined to lead the nation in skyscraper construction.
However, public opinion around these large, dense buildings was steadily turning,
fuelled primarily by the significant shadows they cast across urban areas for long stretches of the day.
The Panic of 1893 was a key turning point.
Regulations were introduced that limited the
height of new buildings in Chicago to just 150 feet (or 43 metres) in an effort to allow
completed vacant buildings to become occupied following the downturn.
In 1895 New York City finally out built Chicago by just one foot with the 303 foot (92 metre)
American Surety Building.
Standing 20 storeys tall on completion, a further five levels
were added during renovation works in the early 1920s.
While steel framed structures were now being built across the United States - in cities
such as Boston, Baltimore and San Francisco
construction in New York City went into overdrive.
With Chicago’s height restrictions in place New York began to pull ahead in the race for the skies.
1902 saw the completion of the iconic Flatiron Building.
Rising from a unique triangular
site, the tower could not have been built without the use of a steel frame.
In 1908 the 186 metre Singer Building joined the skyline and became the world's tallest
building - a title that would go on to reside in Manhattan for well over half a century.
Within a year, the Metropolitan Life Insurance Company completed their 700 foot (213 metre)
tower and took the title from the Singer Building.
The MetLife Tower then remained the world’s tallest until 1913 when the 791 foot Woolworth Building completed.
As in Chicago, concerns around shadowing and building mass began to be raised by the public,
particularly following construction of the vast Equitable Life building in 1915.
Rather than limiting the height of buildings as Chicago did, New York City’s planning
authorities instead passed the 1916 Zoning Resolution requiring setbacks on structures
to preserve light at street level and improve air circulation.
This resolution gave rise to the famous tapered skyscrapers we see in Manhattan today, and
became the blueprint for the regulation of skyscraper construction around the world.
After the First World War, construction once again boomed across the United States.
With height limits imposed and limited development undertaken during the war, Chicago faced a
shortage of office space which saw rents double.
In response, the city’s height limits were
raised to 260 feet (or 79 metres), whilst ornamental features were permitted to stand
up to 400 feet (or 120 metres) high.
This period saw construction of the 468 foot, 134 metre Wrigley Building
and the 568 foot, 173 metre Chicago Temple.
However, despite Chicago’s progress and relaxation in restrictions, New York City’s
dominance began to prove unstoppable.
Back on the east coast - and despite the Great Depression beginning to bite - the 928 foot
(283 metre) Bank of Manhattan Trust Building (now known as 40 Wall Street or the Trump
Building) was completed in 1930.
This structure held the title of world's tallest building for just a few months before being
overtaken by the 1,050 foot, 320 metre Chrysler Building which completed in the same year.
In 1931, the 1,250 foot (381 metre) Empire State Building was completed but remained
largely vacant in its early years as a result of the economic downturn.
The depression, followed by the Second World War marked the start of global dry spell in
skyscraper construction, and the Empire State remained the world’s tallest building
for the next 40 years.
While the race between the two cities stagnated during the 1950s and early 60s, new building
techniques began to emerge that allowed for the construction of even taller skyscrapers.
While elevators had transformed vertical access and made countless tall buildings viable,
their use had also become a limiting factor.
As skyscrapers grew taller, more space was
required for elevator shafts, reducing lettable floor areas and rendering very tall structures uneconomical.
New York City’s World Trade Center overcame this barrier, using a system of stacked elevator
shafts and sky lobbies to significantly increase lettable area.
This new method of elevator configuration, combined with revolutionary “tube frame”
structural design - that moved much of the building’s structural elements to the perimeter
walls - allowed the One World Trade Centre tower to rise to a height of 1,368 feet, dethroning
the Empire State and becoming the world’s tallest building.
A new wave of skyscrapers also began to emerge in Chicago.
The 1,127 foot (344 metre) John
Hancock Center became the city's tallest building in 1969, and was followed by the Aon Center
in 1973 standing 1,136 feet tall.
The Sears Tower (now known as the Willis Tower) went a step further with tube frame design.
By treating the building as a series of interconnected tubes, the “bundled tube” system created
an even stronger structure.
Completion of the 1,451 foot, 442 metre tower in 1974, moved Chicago back ahead of New York
and saw the title of world's tallest building return to the city for the first time in almost
90 years.
New York and Chicago’s race for the skies cooled significantly around the turn of the
millenium as Kuala Lumpur’s Petronas Towers became the world’s tallest building in 1998
and as the nation bounced back from the terror attacks of 2001.
Much of the first 15 years of 21st century saw Lower Manhattan’s ground zero site redeveloped
and the new One World Trade Center reach a height of 1,776 feet.
nodding to the year of American Independence and becoming the tallest building in the United States.
Today, a new wave of skyscraper construction is erupting in these cities, and the race
for the skies has taken on a truly modern dynamic.
For all the taller structures that now define our urban centers around the world
almost everything is owed to the engineering and innovative breakthroughs that came out of
the passionate competition between Chicago and New York.
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