Music, bells, and cannon fire ring out in the Utah desert. About 20,000 people come to watch and listen. Why? They are remembering another sound that was made 150 years ago: a hammer sound. Way back then, workers pounded in the last spikes of the First Transcontinental Railroad—on this very spot in remote Promontory, Utah! People come from as far away as China to celebrate. Many are decked out in old-fashioned dresses, top hats, bonnets, and scarves.

Today we’re used to living in a world where everyone is connected. Need to go into town? Zoom there in a car. Want to visit another continent? Hop on a plane. But 150 years ago, people were much more separated—especially in the United States. They lived far apart in the huge country, divided by deserts, mountains, and forests. Worse, they were separated by ideas. The Civil War had just torn the country in half.

The First Transcontinental Railroad ran 1,800 miles across the United States from San Francisco, California, to Council Bluffs, Iowa. From there it connected to existing rail lines to the East. It made it possible for people to come together. It turned a six-month wagon journey into a 10-day trip by train!

People laid the final rails in 1869. A famous telegram went out: “The last rail is laid. The last spike is driven. The Pacific railroad is completed.” Parties started all over the country! The bells at Philadelphia's Independence Hall rang in celebration. A hundred guns were fired in New York. American flags were hung in cities across the nation.

The railroad was built using horses, oxen, hand carts, wagons, and the strength of U.S. immigrants. Most of them were Irish and Chinese. They worked day and night. They risked their lives blasting through rock to make tunnels, building bridges, and laying track. The last golden railroad spike hammered home on May 10, 1869, had these words on it: “May God continue the unity of our country as this railroad unites the two great oceans of the world.”