No company these days wants to be compared to the United States Postal Service. It is widely understood as America's most ponderous, most pathetic bureaucracy. After all, in an era of instant gratification, what is sadder than "snail mail"?

1908. | (The Smithsonian National Postal Museum via Flickr)

But in the 19th and early 20th centuries, the national mail service was the country's beating heart of innovation.

1922 | An early airmail plane parked next to a U.S. mail truck. | (The Smithsonian National Postal Museum via Flickr)

In 1775, a year before the Declaration of Independence was signed, the Second Continental Congress tasked a committee headed by Benjamin Franklin to create a system for passing along intelligence during the Revolutionary War.

For the newly created and severely underfunded Post Office Department, the monumental task of delivering mail across the colonies necessitated innovation. Instead of building postal offices, the department used taverns, general stores, and other small businesses as mail hubs. Instead of paying for their own carriers and stagecoaches, the department contracted private companies for mail delivery.

1814 | The Village Tavern, by John Lewis Krimmel, depicts the tavern as mail hub, with a mail carrier (left) walking through the door and a desk for writing in the corner. | (Public Domain/Courtesy Toledo Museum of Art)

1885 | City letter carriers with handcarts used to collect and transport mail. | (The Smithsonian National Postal Museum via Flickr)

1905 | A row of one-man mail wagons used to collect mail from city mailboxes. | (The Smithsonian National Postal Museum via Flickr)

In the 19th century, to keep up with the rapidly expanding young nation, the Post Office invested in its own infrastructure. The number of post offices exploded from under 100 in 1790 to more than 76,000 by 1900.

The department also began experimenting with new, faster modes of delivery. In 1893, Philadelphia piloted "pneumatic tube" delivery — a system that used compressed air to shoot cylindrical capsules filled with mail through an underground network of pipes.

The system was soon adopted by other large cities. In New York, pneumatic tubes could send six million pieces of mail a day at 30 miles an hour across the boroughs.

1897 | Workers at a New York City post office load cannisters of mail into pneumatic tubes. | (The Smithsonian National Postal Museum via Flickr)

In Alaska, the Post Office used dog sled mail carriers. In Washington, D.C., postmen swapped horse-drawn carriages and clunky wagons for early iterations of the motorcycle: two- and three-wheeled bikes that needed to be pedaled or hand-cranked to ignite the small engine.

1910 | Dog sleds transporting mail in Alaska. | (The Smithsonian National Postal Museum via Flickr)

1912 | A mail motorcycle in Washington, D.C. | (The Smithsonian National Postal Museum via Flickr)

Meanwhile, the Post Office took advantage of the massive industrial advances of the era. In 1864, the postal department opened the Railway Post Office, where highly trained clerks picked up and sorted mail aboard high-speed passenger trains.

Starting in 1918, the Post Office built and operated the nation's first airmail service. In 1941, the department tested out Highway Post Offices, which mirrored the railway system using buses.

Not only did improvements in transportation help the country's mail service deliver parcels faster and more efficiently, but the revenue from Post Office contracts subsidized several fledgling companies and industries.

Thanks to the airmail service, for example, government contracts made up to 90 percent of business for early airline companies at a time when Americans feared the idea of air travel.

1918 | New York City Postmaster Thomas G. Patten hands Lt. Torrey Webb a bag of letters for one of the first regularly scheduled airmail flights in the U.S. | (The Smithsonian National Postal Museum via Flickr)

1920 | Clerks sort mail inside the tight quarters of a Railway Post Office car. | (The Smithsonian National Postal Museum via Flickr)

1941 | The first Highway Post Office bus in Strasburg, Virginia. | (The Smithsonian National Postal Museum via Flickr)

The pioneering Post Office had plenty of innovated misses as well. An early three-wheeled delivery truck, nicknamed the "mailster," could be tipped over by a powerful gust of wind, or an overly aggressive dog.

And the department's 1959 mail-by-missile test — which successfully sent 3,000 pieces of mail in the cannister of a missile to its intended target 100 miles away — was never put to use since it could never hold enough mail to make it worthwhile.

1959 | A U.S. Navy Regulus I missile, containing mail, is fired from the USS Barbero for the first, and last, official missile mail experiment. | (The Smithsonian National Postal Museum, via Flickr)

1955 | The "mailster." | (The Smithsonian National Postal Museum via Flickr)

The national postal service's great period of innovation came to a close toward the end of the 20th century. Postal workers began to unionize, new private startups like FedEx and UPS competed for business, and Congress introduced more and more legislation regulating what was by now the United States Postal Service.

"The history of the U.S. Postal Service is an ongoing story of enormous depth and breadth," wrote former U.S. Postmater General John E. Potter in 2006, "rooted in a single, great principle: that every person in the United States — no matter who, no matter where — has the right to equal access to secure, efficient, and affordable mail service."

1954 | A carrier delivering mail in a right-hand drive van, similar to the ones seen on the road today. | (The Smithsonian National Postal Museum via Flickr)