PROMONTORY, Utah (Reuters) - As train bells clanged and steam whistles tooted, thousands of people on Friday witnessed the re-enactment of a ceremony in Utah’s high desert that marked the completion of the first railroad to span the North American continent 150 years ago.

A replica of the historic Jupiter steam locomotive rolls across Promontory Summit on the 150th anniversary of the completion of the Transcontinental Railroad at Golden Spike National Historical Park in Promontory, Utah, U.S. May 10, 2019. REUTERS/Terray Sylvester

The spectacle - recreating a historical moment that took place on May 10, 1869 - featured the driving of a golden spike into a replica of the final railroad tie that joined the Union Pacific Railroad with the Central Pacific Railroad.

The linking of East and West was the culmination of a 6-1/2-year feat of 19th-century engineering that transformed the American frontier as the nation was emerging from a bloody civil war. The site at Promontory Summit, 66 miles (106 km) northwest of Salt Lake City, is now preserved as a national historic park, named Golden Spike.

Addressing Friday’s crowd as keynote speaker, Pulitzer Prize-winning author and historian Jon Meacham said that the achievement at a time of unprecedented national upheaval offered a lesson in political perspective.

“If Americans want to know what is possible, come here,” he said. “Big ideas and big dreams are the best stuff of American history.”

Friday’s festivities featured full-size working reproductions of the two steam engines nosing up to each other, cowcatcher to cowcatcher, in a re-creation of an iconic photo from the day the first Transcontinental Railroad was completed a century and a half ago.

TELEGRAPH FLASH: ‘DONE’

That picture captured throngs of bearded crewmen raising a toast to the occasion as they clamored around the two engines, Central Pacific’s No. 60 Jupiter and Union Pacific’s No. 119. Participants in Friday’s event struck similar poses for a series of photos inspired by the original.

The photo opportunity followed a costumed re-enactment of 1869’s ceremonial driving of the last spike into a specially built railroad tie, connecting the finished 1,776-mile (2,858-km) line of newly laid track between Sacramento, California, and Council Bluffs, Iowa.

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The actual spike, cast in 17.6-karat gold, and three other ceremonial spikes of gold and silver alloys, were tapped into pre-drilled holes with a silver-plated mallet. Shiny replicas were used in the re-enactment.

The moment was punctuated by whistle blasts, hissing steam and clanging bells of the two locomotives, and by a staging of the original coast-to-coast telegraph bulletin announcing the ceremony’s end - the single-word message “Done.” The performance of a live musical “re-imagining” of the 1869 ceremony followed.

The actual commemorative spikes were immediately replaced by ordinary iron spikes at the end of the 1869 event to prevent them from being stolen. Some of them, along with the silver mallet and related artifacts, were on display this week at the Utah State Capitol in Salt Lake City.

Re-enactments of the 1869 ceremony have been presented weekly for many years at the Golden Spike historic park. But this year’s event, kicking off a three-day festival of music, theater and special exhibits at the site, drew a crowd organizers said numbered about 20,000 people.

TRANSFORMATION AND PRIDE

The advent of the railway, which cut cross-country travel time from many months to just a week, greatly accelerated Anglo-European settlement of the American West and aligned it politically with the Union states of the North. It also hastened the demise of the Plains Indians, as well as the bison herds on which they depended.

Construction of the railroad drew many thousands of immigrants to the United States, especially Irish and Chinese laborers who formed the backbone of the project’s workforce.

The Chinese, accounting for the bulk of the Central Pacific’s crews, faced especially harsh conditions as they carved and blasted railbeds through rock over rugged terrain in the Sierra Nevada mountains, all without power tools and for less pay than their white counterparts.

In a taped video message played at Friday’s ceremony, China’s current ambassador to the United States, Cui Tianakai, saluted the railroad as a “telling example of how the Chinese and American people can come together to get things done and make the impossible possible.”

Ireland’s U.S. ambassador, Daniel Mulhall, attended the celebration in Utah, raising a toast to the thousands of Irish immigrants who labored on the Union Pacific side of the project.