<strong>California Zephyr: </strong>Amtrak's California Zephyr train line runs daily between Chicago and San Francisco (pictured here on March 25, 2017). The 2,438-mile journey takes around 52 hours. <br /><br />
California Zephyr: Amtrak's California Zephyr train line runs daily between Chicago and San Francisco (pictured here on March 25, 2017). The 2,438-mile journey takes around 52 hours.

Joe Raedle/Getty Images
<strong>The route: </strong>The train sets off from Chicago's Union Station, travels through the plains of Nebraska to Denver, across the Rocky Mountains to Salt Lake City, and then through Reno and Sacramento into Emeryville then San Francisco.
The route: The train sets off from Chicago's Union Station, travels through the plains of Nebraska to Denver, across the Rocky Mountains to Salt Lake City, and then through Reno and Sacramento into Emeryville then San Francisco.
Joe Raedle/Getty Images
<strong>Highlights: </strong>Scenic spots en route include the Sierra Nevada, Moffat Tunnel, Colorado's Gore Range, Byers and Glenwood Canyons, Winter Park, Truckee River, Donner Lake, San Pablo Bay and the Carquinez Strait and Glenwood Springs (pictured). <br />
Highlights: Scenic spots en route include the Sierra Nevada, Moffat Tunnel, Colorado's Gore Range, Byers and Glenwood Canyons, Winter Park, Truckee River, Donner Lake, San Pablo Bay and the Carquinez Strait and Glenwood Springs (pictured).
Joe Raedle/Getty Images
<strong>Proposed budget cuts:</strong> In the US, passenger rail travel is subsidized by federal funding. The threat of budget cuts has been hanging over less profitable lines for a number of years.
Proposed budget cuts: In the US, passenger rail travel is subsidized by federal funding. The threat of budget cuts has been hanging over less profitable lines for a number of years.
Joe Raedle/Getty Images
<strong>The numbers:</strong> The California Zephyr carried 417,322 passengers in fiscal year 2016, an 11.2% increase over the year before.
The numbers: The California Zephyr carried 417,322 passengers in fiscal year 2016, an 11.2% increase over the year before.
Joe Raedle/Getty Images
<strong>Long-distance riders: </strong>In fiscal year 2016, numbers on Amtrak's 15 long-distance lines were up 3.7% versus the year before, with close to 4.7 million riders.
Long-distance riders: In fiscal year 2016, numbers on Amtrak's 15 long-distance lines were up 3.7% versus the year before, with close to 4.7 million riders.
Joe Raedle/Getty Images
<strong>Northeast Corridor: </strong>Should cuts to long-distance funding go ahead, the money could be directed instead to the busier Northeast Corridor lines, which served close to 12 million riders in fiscal year 2016.
Northeast Corridor: Should cuts to long-distance funding go ahead, the money could be directed instead to the busier Northeast Corridor lines, which served close to 12 million riders in fiscal year 2016.
Joe Raedle/Getty Images
<strong>Sleeping options: </strong>On board the California Zephyr, Travelers can sleep in their coach seats or upgrade to a roomette or bedroom in one of the Superliner sleeping cars.
Sleeping options: On board the California Zephyr, Travelers can sleep in their coach seats or upgrade to a roomette or bedroom in one of the Superliner sleeping cars.
Joe Raedle/Getty Images
<strong>Illinois: </strong>Galesburg is one of the Zephyr's stops in Illinois. The town was once a stop on the Underground Railroad, used by enslaved African-American in the 19th century to escape to free states and to Canada.
Illinois: Galesburg is one of the Zephyr's stops in Illinois. The town was once a stop on the Underground Railroad, used by enslaved African-American in the 19th century to escape to free states and to Canada.
Joe Raedle/Getty Images
<strong>History: </strong>Amtrak has run the California Zephyr service since 1983. The original California Zephyr, operated by three other railroads, ran between 1949 and 1970.
History: Amtrak has run the California Zephyr service since 1983. The original California Zephyr, operated by three other railroads, ran between 1949 and 1970.
Joe Raedle/Getty Images
<strong>Superliner:</strong> Amtrak uses Superliner railcars on the service. Superliners first entered service in 1979 and close to 480 of them were built.
Superliner: Amtrak uses Superliner railcars on the service. Superliners first entered service in 1979 and close to 480 of them were built.
Joe Raedle/Getty Images
<strong>Communities: </strong>Amtrak CEO and President Wick Moorman says that budget cuts could potentially impact 500 communities.
Communities: Amtrak CEO and President Wick Moorman says that budget cuts could potentially impact 500 communities.
Joe Raedle/Getty Images
<strong>Connections: </strong>"Amtrak operates 15 long-distance trains across the nation and these routes offer the only Amtrak service in 23 of the 46 states we serve," Business Insider quotes Moorman as saying in a statement. "These trains connect our major regions, provide vital transportation to residents in rural communities and generate connecting passengers and revenue for our Northeast Corridor and State-Supported services."
Connections: "Amtrak operates 15 long-distance trains across the nation and these routes offer the only Amtrak service in 23 of the 46 states we serve," Business Insider quotes Moorman as saying in a statement. "These trains connect our major regions, provide vital transportation to residents in rural communities and generate connecting passengers and revenue for our Northeast Corridor and State-Supported services."
Joe Raedle/Getty Images
<strong>The future: </strong>It's not known yet if the proposed budget will be approved by Congress, or even how those cuts might be implemented. But from the 1950s onwards, many railroads have been driven out of business due to the rise of the motor car and of the airline industry. The long-distance lines might well be running out of track.
The future: It's not known yet if the proposed budget will be approved by Congress, or even how those cuts might be implemented. But from the 1950s onwards, many railroads have been driven out of business due to the rise of the motor car and of the airline industry. The long-distance lines might well be running out of track.
Joe Raedle/Getty Images
The end of the line for American long-distance trains?
CNN  — 

The railroads that once helped build the United States today still carry thousands of people across the country on journeys of business, discovery and pleasure.

But their role in opening up the vast open spaces between the Atlantic and Pacific Oceans could soon be drawing to a close.

In March, President Donald Trump proposed a national budget that would terminate federal support for Amtrak’s long-distance train routes.

The above gallery takes a look at one of the services under threat as it hauls its passengers on a typical journey through wide screen American landscapes.

Can Europe’s last sleeper trains survive?

11 of the world’s most luxurious train journeys

What it’s like to ride India’s train system for days at the time