(triumphant music) - [Narrator] The place, Promontory Summit, Utah.

The time, May 10th, 1869.

- Welcome, the last spike needed to connect the Atlantic and the Pacific.

- [Narrator] Here, 690 miles east of Sacramento, 1,086 miles west of Omaha, officials of the Central and Pacific Railroads met to celebrate the completion (audience applauds) of the first Transcontinental Railroad.

(twangy music) (train whistle blows) (bell dinging) - My name's David Kilton, I am an interpretive ranger here at Golden Spike National Historic Site.

I love history, and then sharing this story, I mean, it was a huge kind of pivotal time in the change of our nation.

It started during the Civil War, leading right into the Industrial Revolution and really how that changed everything within the country.

Time zones were established because of the Transcontinental Railroad.

Communication improved with this project because they built the telegraph right alongside the rails.

And it really was the end of the old West as a wild, untamed land.

(engine hissing) Every Saturday and holiday throughout the summer, we do reenactments of the ceremony that was held on May 10th, 1869 with a period-dressed cast.

(actors applaud) - The last spike needed to unite the Atlantic and the Pacific by a new line of trade and commerce is about to be driven to its place.

To perform this act, the East and the West have come together.

I'm Richard Felt.

I've played the part of W.H.

Harkness.

I've been playing the part for 44 years.

I was in the original reenactment in 1969 when the park was opened.

I usually thank the people from out of state for bringing the Utahns up here because the Utahans don't seem to want to come by themselves, but whether it be because they're interested in trains, whether they're interested in local history, whether they're interested in national history, or for that matter, international history, all had an impact with what happened here.

I'm a little jealous of the engineers because they get paid for playing with these two trains, and I don't get to play with them.

- My name is Mike Oestreich, and I'm a locomotive fireman here at Golden Spike National Historic Site.

Everything I've learned about steam has been right here on the job.

We have an apprentice program where someone inexperienced, like me, would start and learn from the people that learned from the people before them, keep handing that down.

Being a steam locomotive, it sounds like they're breathing.

There's respiration going on.

They're exhaling hot vapor and they're sucking in air, just like we do.

(train whistle blows) (bell dinging) There's a lot of maintenance that goes on on these locomotives.

Lots of moving parts on 'em, everything's gotta be oiled, a few things have to be greased.

There's a lot of polishing work we gotta do also.

You can see a lot of brass on 'em, that gets cleaned up every day.

As far as the history of our country goes, when the Civil War ended, this railroad was one of these massive national projects where people from both sides, freed slaves, former soldiers, immigrants, everybody came together and worked on this railroad, and essentially bound the country together.

It's important to tell that story.

- Many others have compared this event to another event that happened just 100 years later.

1869 to 1969, man went to the moon.

- [Astronaut] That's one small step for man, one giant leap for mankind.

- And whether kind of coincident or not, just across the way is what they connected it with.

ATK is where they built the boosters.

(fire roaring) Once again, many different people coming together in a time of trial within the nation, overcoming challenges, and completing what was thought to be an impossible challenge.

(lively bluegrass music) (train whistle blows)