[ Brakes screech ] After the Civil War, you have this powerful young country spreading from coast to coast, all under one flag.

Factories were being built and goods were in high demand, especially in the West, where towns and cities were springing up overnight.

But the U.S. had major supply chain issues -- how to get those goods from point A to point B.

And the best way to transport goods at the time was by train.

But there wasn't enough labor in the country to build the network of railways we needed, connecting east to west, north to south.

So guess who came in to build the thousands of miles of railway tracks?

Mexican and Mexican American laborers, known as traqueros, who represented almost 60% of the entire workforce.

And thanks to the work of the traqueros, the transcontinental railroad changed the landscape of this country and commerce forever.

[ Train whistle blowing ] -Traqueros built the Southwest, along with their Chinese counterparts, their Irish counterparts.

They're building the infrastructure that makes it possible for the rise of cities like Phoenix, for the rise of cities like Los Angeles.

Without their labor, these cities do not exist.

Mexican railway workers gain in importance and numbers, especially after the U.S. exclusion of Chinese and Chinese American workers.

-We can pay a great deal of attention to the importance of Mexican labor for the construction and creation of much of the Southwest.

♪♪♪ [ Train whistle blowing ]