Millions of people have marveled at the beauty of New York City’s Grand Central Terminal. But how many know the remarkable story of how it was built?

To get started, the New York Central Railroad had to bore deep into Manhattan bedrock to excavate two levels of tunnels, eventually removing some three million cubic yards of material. To pay for the construction, the railroad charged developers for “air rights”: the right to construct buildings over the former open rail yard, which had been paved over. Many of the city’s best-known buildings eventually rose over the site, including the Waldorf-Astoria hotel.

Construction of the new Grand Central lasted ten years, from 1903 to 1913. During that time, amazingly, trains continued to come and go without interruption!

This year we’re celebrating the 100th birthday of New York’s Grand Central Terminal, one of the most majestic public spaces in the world. But if you look back in history, this architectural masterpiece’s beginnings were anything but grand.

The site was originally home to the Grand Central Depot, built by railroad tycoon Cornelius Vanderbilt and opened to the public in 1871. The depot sat next to an open rail yard crammed with noisy, smoke-belching steam locomotives. When two trains en route to the depot collided on January 8, 1902, killing and injuring dozens of passengers, pressure mounted on the New York Central Railroad to switch to electric trains. By the end of that year, the railroad’s chief engineer, William Wilgus, began developing plans for a new Grand Central Terminal, one in which electric trains would run underground, beneath a new building.

You can mark 100 years of history with , including a sheet of ten Grand Central Terminal Express Mail stamps, plus an envelope bearing the stamp along with a First Day of Issue color postmark. The black and gold postmark features the terminal’s famous four-sided clock and the phrase, “Grand Central, 100 Years.”