On May 10, 1869, businessman Leland Stanford hammered a golden spike into the railroad tracks at Promontory Summit in Utah. For six years, tens of thousands of people had worked to lay almost 2,000 miles of track across the United States. Now, at long last, the first Transcontinental Railroad was complete. Suddenly, with that final spike in place, a trip across the country would take just seven days! That might seem like a long time by today’s standards, but before the advent of the railroad, the journey west took up to six months!

If you’ve ever owned all four railroads in the board game Monopoly, then you have some idea how important trains were in the Gilded Age. Over the next 50 years, the railroad, nicknamed the Iron Horse, would change almost everything about life in the United States, from shopping and travel to big business and government.

The story of the Iron Horse began long before Stanford. In the early 1800s, as white Americans moved out west, people began looking for faster ways to travel and deliver things to their new homes. At the time, most settlers used animals or boats to get around, but they also used rails.

People had been using rails long before then to help cars slide down hills. In fact, America’s first “gravity road,” as these tracks were known, was built way back in 1764. In addition to gravity, these early railroad cars used animals for power. They were a far cry from the whistling, chugging trains we think of today.

Then in 1804, a British inventor named Richard Trevithick combined rails with a newer invention—steam power. He created the first steam locomotive to run on rails. In 1830, the Baltimore and Ohio Railroad opened the first railroad in the United States using a steam locomotive they named Tom Thumb.

By 1850, a short 20 years later, American railroad companies had laid 9,000 miles of track. That’s about the distance from New Zealand to New York!

In 1848, a carpenter named James found something incredibly valuable while working in Northern California. He struck gold! Over the next year, nearly 100,000 people would travel to the new gold country hoping to get rich. In 1850, California became the 31st state in the Union. The United States now touched both the Pacific and the Atlantic Oceans, and people started asking the government for a railroad to speed up the trip between the coasts.

To help build this railroad, the United States Congress passed a law called the Pacific Railway Act. The law allowed two companies to borrow money from the government. It also granted the companies land along the planned path. In 1863, the Central Pacific Railroad began laying track in Sacramento, California while the Union Pacific Railroad started work in Omaha, Nebraska, 1,776 miles away.

In the West, the Central Pacific’s route led them through the Sierra Nevada Mountains. Most of the workers there were men who had come from China. The work was dangerous. In some places, bridges had to be built between mountainsides. In others, workers filled holes with explosive powder to blast away rock. In one area where walking was too dangerous, the men drilled the holes while hanging in baskets lowered from the cliffs above.

In the East, the Union Pacific had trouble finding people to do the hard work of building a railroad. That changed in 1865 when the Civil War ended, as thousands of soldiers started looking for jobs. As it turned out, many men who had recently arrived in the United States were also in need of work. The Union Pacific hired soldiers well as Irish, German, and Italian immigrants to help build the eastern end of the railroad.

Four years later, the two railways joined at Promontory Summit, and because the new railroad crossed the continent of North America, it became known as the Transcontinental Railroad.

After that, the Iron Horse really picked up steam. Fifty years after the end of the Civil War, workers had laid enough track to get to the moon from Earth! Forty-nine out of every 50 people who traveled from one city to another used a railroad, and 85,000 train stations had sprung up across the United States. Imagine, for every Starbucks in the country today, there were five railroad stations by the end of the Gilded Age!

Have you ever called someone who lives far away from you? Was their time zone different from yours? If so, you have the railroads to thank for that. With the entire country joined by train routes, U.S. railroad companies started using four set time zones to make sure their trains ran on schedule.

Stores could now deliver things like toys or clothes much faster than before. Companies began selling their products through the mail—long before Amazon ever made its first website. In the 1890s, Montgomery Ward and Company sold 24,000 items through its mail-order catalog. In 1894, Sears, Roebuck & Co. printed their first catalog. It was a whopping 322 pages long! With the invention of refrigerated cars, people even delivered meat by train, and the meat-packing business boomed.

Meanwhile, railroad companies wanted to make sure there were enough customers for all the things they were carrying, so they did whatever they could to get people to move west. They lowered ticket prices for people who settled in towns by their routes. They even gave free tickets to newspaper writers who wrote exciting stories about the West.

Thanks in large part to the railroads, millions of people moved westward during the Gilded Age.

When you think of thieves of the Gilded Age, you might think of train robbers like Jesse James and his gang of outlaws. But there was a different sort of robber making headlines at the same time. Believe it or not, these “robber barons,” as they were called, were often the owners of the railroads themselves.

Railroad companies received money from customers and the government. They also sold stock, or pieces of their company, in a place called the New York Stock Exchange. In these ways, a few companies ended up with huge amounts of money. Sometimes big companies would merge, or join with each other, and form even bigger companies.

Because of these mergers, by 1900, seven people owned 70 percent of the country’s railroads! These railroad tycoons included Cornelius Vanderbilt, who was the richest man in the world when he died, and Jay Gould, who also owned a company that delivered messages called telegrams.

Just like in Monopoly, the more railroads someone owned, the more power that person had. However, unlike in Monopoly, not everyone played by the rules. Big railroads made some customers pay more than others, which often hurt farmers and smaller companies. Farmers needed railroads to sell the food they grew, so they had no choice but to pay the high prices set by the robber barons. In the same way, railroad workers were forced to take the low pay their bosses gave them.

Railroad tycoons even bullied the government to pass laws that helped their businesses. Jay Gould gave politicians money to get what he wanted. These bribes were and still are against the law. Many big businessmen simply bought the railroads they needed to succeed. Steel tycoon Andrew Carnegie owned mines and machines for making steel, machines to turn the steel into railroad cars, and railroads themselves.

As the Gilded Age drew on, some people fought back against the tycoons and robber barons. In 1887, pressure from farmers convinced Congress to create something called the Interstate Commerce Commission (ICC). The job of the ICC was to investigate railroad rates and see if prices were fair. At first, the ICC wasn’t strong enough to change how railroads did business. So Congress passed another law that gave the ICC new powers, including the authority to say when rates were too high.

Meanwhile, in 1890, a senator named John Sherman helped write a law called the Sherman Antitrust Act. The law stopped big companies from teaming up in ways that made it impossible for smaller companies to succeed. President Theodore Roosevelt later used the law to break up big companies into smaller ones.

Railroad workers also fought for better pay. In 1877, the Baltimore and Ohio Railroad lowered its workers’ pay. Some angry employees decided to block trains from leaving the station until their pay was raised. This event was known as the Great Railroad Strike of 1877, and it spread quickly across the country.

As more employees demanded better pay, they began to form groups called labor unions. These unions were teams of workers who came together to ask for fair treatment. In 1892, a man named Eugene Victor Debs formed a labor union called the American Railway Union (ARU). So when the Pullman Palace Car Company lowered its workers’ pay in 1894, ARU members decided to stop handling any railroad cars made by Pullman.

Before long, 125,000 people stopped working on at least 20 railroads. In both strikes, the government sided with the railroads to get the trains running again. Even so, the Great Railroad Strike and the Pullman Strike showed Americans just how important railroads and railroad workers were to everyday life in the Gilded Age.

In the same way that railroads once took the place of horse-drawn carriages, new forms of travel began to take the place of railroads. In 1903, the Wright Brothers flew the first airplane. Earlier that same year, Henry Ford started the Ford Motor Company. Five years later, he began selling a gasoline-powered car called the Model T.

Today, in addition to planes and cars, people use trucks, buses, and barges to travel or ship things to customers. And just like real horses didn’t disappear after the invention of railroads, the Iron Horse also stayed alive and well. Many businesses still use railroads to deliver goods, and millions of people ride trains every day in big cities. People have invented trains that are much faster than the ones from the Gilded Age. Some high-speed rails can travel almost as fast as airplanes, and new lines are up and running around the world.

On the other hand, if you ever want to remember the good old days, you can still ride many of the lines built during the Gilded Age. You can even travel along parts of the original route of the First Transcontinental Railroad. It may not be the fastest way to travel anymore, but it is a reminder of a bygone era—an era that changed the history of the nation.