One of the seminal events to unify the young United States is being commemorated in the state of Utah.

Crowds gathered to witness a re-enactment of the day 150 years ago when a golden spike was hammered into place to complete the Transcontinental railway, linking the east and west coasts.

The Central Pacific and Union Pacific Railways joined together at Promontory Summit, 66 miles northwest of Salt Lake City

The transport link slashed travel times from months to a week, and quickly spread Anglo-European influence.

Image copyright Getty Images Image caption Men re-enact the moment the two railway lines were connected

Image copyright Reuters Image caption A replica of the historic 119 steam locomotive rolls across Promontory Summit

Image copyright Reuters Image caption Crowds watch as replicas of the historic Jupiter and No 119 steam locomotives meet on the 150th anniversary

The anniversary was marked by speeches, music and a re-enactment of the 'golden spike' moment.

When the two trains met in 1869, crewmen were pictured toasting the moment with bottles of whiskey.

The achievement was announced across the country by telegraph with the single-word message "done."

While the railway boosted economic development, it also displaced Native American Tribes, and some 1,200 Chinese railway workers died during the construction process.

Image copyright Reuters Image caption Back in the day, the achievement was announced across the country via telegraph

Image copyright Getty Images Image caption The Jupiter (left) and the 119 steam engines make their way into place

The Pacific Railway Act was signed in 1862 by President Abraham Lincoln.

Two companies were granted land rights and grants to build railways.

The Central Pacific Railroad started in Sacramento, California while the Union Pacific Railroad started in Council Bluffs, Iowa. Both met at Promontory Summit on May 10 in 1869.

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