1876 Centennial Exhibition transformed Phila.

A century after helping set the course of the nation, Philadelphia threw a months-long Centennial celebration that dazzled 10 million visitors with its show of industry and innovation.

"The Centennial Exhibition was a major national event and a transformative event in Philadelphia," said Randall Miller, a history professor at St. Joseph's University. "It was a statement about the advance of Philadelphia, the power of Philadelphia."

Planning for the country's 100th birthday celebration had begun a decade earlier. The idea was to hold a world's fair in the United States in Fairmount Park. Because of the city's manufacturing prowess, the exhibition aimed to show off what Philadelphia could do, 100 years after the Founding Fathers signed the Declaration of Independence.

To get ready, the city buzzed with projects. Rail lines were laid to stretch from Center City into the suburbs, changing the area for generations to come. New bridges were built across the Schuylkill, including one at Girard Avenue that, at 100 feet wide, was believed to be the widest of its kind in the world.

The busiest construction zone was in West Fairmount Park, where 200 buildings rose. The largest were the Main Exhibition Building, Machinery Hall, Agricultural Hall, Memorial Hall and Horticultural Hall. Only the latter two remain.

Just outside the park, builders constructed temporary hotels that housed thousands of visitors at a cost of about $1 a night, and offered beer for five cents a glass.

The ports and streets bustled as visitors from 50 countries arrived to set up displays. The French ship Labrador - 400 feet long, and carrying 5,000 tons of goods - attracted much attention, as it was the largest vessel that had ever come up the Delaware.

Visitors from Japan drew stares when, instead of using the wheelbarrows they were given to roll goods across town, they picked up the wheelbarrows and carried them as well.

While the exhibition was originally slated to open in April 1876 to mark the anniversary of the Battles of Lexington and Concord, construction delays pushed the unveiling to May. On May 10, The Inquirer devoted almost the entire front page to a map of the fairgrounds, and gave over most of another page to the details of what was to come.

"The occasion will be grand and imposing," the paper promised, "as the magnificence of the event itself demands." Four thousand soldiers from the local militia escorted President Ulysses S. Grant to the fairgrounds.

After a speech, a song, and a poem, Grant went to Machinery Hall and set in motion the massive Corliss Engine, considered a wonder of the fair, which supplied power by means of cogs and underground shafts to 800 other machines.

By all reports, visitors were dazzled by the display of Philadelphian and American ingenuity. Among the items first unveiled were Heinz ketchup, the Pullman Palace Car, the Westinghouse air brake, and Thomas A. Edison's quadruplex telegraph, which transmitted multiple messages in opposite directions down the same wire at the same time.

Alexander Graham Bell's new telephone drew crowds. "My God, it talks," Emperor Dom Pedro II of Brazil is supposed to have said.

The summer of 1876 was one of the hottest in years and that adversely affected attendance, which averaged about 25,000 daily visitors through August. But no one held back on July Fourth.

People began celebrating the day before, when more than 300,000 jammed Chestnut and Broad Streets for a parade. "When the State House bell struck twelve, and the new century of independence had begun, the whole town seemed to have broken out in one mighty shout. People walked the streets or slept on the steps all night long," wrote J. Thomas Scharf and Thompson Westcott in History of Philadelphia, 1609-1884. "And after the parade of fireworks in Fairmount Park, the people of Philadelphia were thoroughly exhausted with their two days of almost unparalleled rejoicing."

The Inquirer called it "one grand and noble offering at Liberty's shrine."

With September came cooler temperatures and more visitors. The fair averaged 60,000 daily visitors that month, then 88,000 in October and 99,000 in November. When the exhibition closed on May 10, more than 10 million people had visited Philadelphia, including the presidential candidates, Republican Rutherford B. Hayes and Democrat Samuel J. Tilden.

The exhibition inspired people who weren't wealthy to embrace the idea of taking a long trip for leisure, and Philadelphia became one of the country's first tourist meccas.

How great was the fair's impact?

In the immediate aftermath, the Chicago Daily Tribune crowed that the old Philadelphia was gone and that the city was "as cosmopolitan as Paris and as lively as Chicago." The Inquirer claimed that, for a few months at least, Philadelphia was the "principal city in the United States."