There are many natural wonders in the United States. Today, we take you to seven man-made wonders in America.
Against the city's gleaming spires,
Above the ships that ply the stream,
A bridge of haunting beauty stands –
Fulfillment of an artist's dream.
That poem is about our first man-made wonder -- the Brooklyn Bridge in New York City. It extends more than 480 meters over the East River to connect the areas of Brooklyn and Manhattan. A famous bridge builder David B. Steinman wrote the poem. But he did not build the Brooklyn Bridge.
It was the dream of another man, John A. Roebling. He was a member of the design team and became chief engineer of the building project in 1867. Sadly, he became sick and died before work even started. He had an accident when visiting the area where the bridge was to be built
Building began in 1870. It was very dangerous. Few records were kept on such events. But, historians say between 20 and 30 men died as a result of the building project. Some died from falling off the bridge or from being struck by equipment.
Others died or were injured from working in the structures called caissons. These lay deep below the surface of the Earth. The workers would get a pressure sickness called the bends.
John Roebling's son, Washington, was severely disabled by the bends. He had been named chief engineer of the Brooklyn Bridge project soon after his father died. Washington Roebling continued the work from his home after he was disabled.
The Brooklyn Bridge opened on May 24, 1883. At the time, it was the longest suspension bridge in the world. It is still a beautiful structure. The bridge has tens of thousands of suspension wires that spread many meters across and up and down to towers on each side. From a distance the many wires look like the stringed musical instrument called the harp. The center of the Brooklyn Bridge rises almost 40 meters above the East River. It is one of the most famous and beloved New York City landmarks.Another bridge makes our list of the seven man-made wonders. This one is in northern California.
The Golden Gate Bridge is named after the waterway it crosses. The Golden Gate Strait lies between the Pacific Ocean and the San Francisco Bay. The bridge over it links the city of San Francisco with Marin County.
Joseph Strauss was the chief engineer of the Golden Gate Bridge. Building began in 1933. The bridge opened in 1937. It is almost 1,300 meters long. It was the longest suspension bridge in the world for almost 30 years. Then, in 1964, the larger Verrazano Narrows bridge opened in New York City.
Joseph Strauss used newly developed protective equipment for the men who worked on the bridge. These included a special safety net under the bridge. But still, 11 men were killed during construction
The color of the bridge, International Orange, is very important. It was chosen partly because it is easier to see through the heavy fog that often covers San Francisco. Many people consider the Golden Gate Bridge the most beautiful bridge structure in the world.
Joseph Strauss wrote a poem about his bridge when the work was done. Here is a part of "The Mighty Task is Done":
At last the mighty task is done;
Resplendent in the western sun
The Bridge looms mountain high;
Its titan piers grip ocean floor,
Its great steel arms link shore with shore,
Its towers pierce the sky.
Our next man-made wonder is as famous a landmark in the Midwest United States as the first two are on the East and West Coasts. The Gateway Arch in Saint Louis, Missouri is the tallest freestanding monument in the nation. The shiny, steel curve rises to almost 200 meters. Below, the arch is exactly as wide as it is tall.
The famous Finnish American building designer, Eero Saarinen, designed the Gateway Arch during a national competition in the late 1940s. However, building did not begin until February, 1963. It was completed in October, 1965. Later a transport system was added to permit people to visit an observation area inside the top of the arch.
The Gateway Arch rises above the Mississippi River. It was named in honor of Saint Louis, which was historically called "The Gateway to the West."There is one place in America that almost everyone agrees is a man-made wonder: South Dakota's Mount Rushmore
Giant faces of four great American presidents are cut into the rock near the top of Mount Rushmore in the Black Hills. Each face is about 18 meters high.
Sculptor Gutzon Borglum was chosen to create the Mount Rushmore memorial. It was completed in 1941, after 14 years.
Each president represents important values in America. George Washington led the cause for independence. Thomas Jefferson represented the belief in equality. Abraham Lincoln ended slavery and saved the Union. And Theodore Roosevelt was a conservationist and symbol of the progressive spirit of America.We go next to one of the largest and most difficult structures ever built in the United States: Hoover Dam. The dam is in the Black Canyon, near Las Vegas, Nevada. It controls the water of the Colorado River and produces electric power.
Workers began to build Hoover Dam in 1931. They finished in just five years.
More than 20,000 men worked on the project. It was very dangerous. Ninety-six workers were killed. Many others were injured.
The Hoover Dam is 221 meters tall. It weighs more than six and one half million tons. At the time, it was the largest and tallest dam in the world. And it was one of the largest producers of electric power ever built.
Hoover Dam also created Lake Mead, the largest man-made lake in AmericaAnother man-made wonder of the United States was built long before the nation was established. About 900 years ago, the Ancestral Puebloan people built villages high in the walls of canyons in Mesa Verde, Colorado. Six hundred cliff dwellings are now part of the Mesa Verde National Park.
Visitors can stand at the top of the mesas and look into the dwellings almost hidden in openings of the rock walls. The Puebloan people cut small steps into the rock. A series of such steps connected buildings containing hundreds of rooms.
The rock walls have protected the buildings from severe weather in the area.
So they remain mostly unchanged in the hundreds of years since they were built.Our final man-made wonder is in the northwestern city of Seattle, Washington. The Space Needle was built as the central structure for the 1962 World's Fair.
Edward Carlson designed the 184 meter tall structure. The Space Needle has a wide base on the ground. It is narrow in the middle. On top is a large ring-like structure.
The structure was meant to look like a "flying saucer," a vehicle that was popular in science fiction space travel stories. The saucer includes an observation area and eating place. The restaurant slowly turns to provide visitors with a 360 degree view of Seattle.
The Space Needle was not very costly. The building project cost about 4,500,000 dollars. It was designed and completed in about a year and opened on the first day of the World's Fair.
Today, the Space Needle is the most popular place for visitors to Seattle. And it remains the internationally known symbol of the city.