In 1803 Meriwether Lewis and William Clark embarked on their famed journey up the Missouri River to the Pacific Ocean. The expedition took about two years and included an 18-mile portage that involved hauling several-ton boats on crude carts. In a sense, the expedition was the first American road trip, but it was no vacation.

Exactly one century later, in 1903, Dr. Horatio Nelson Jackson of Burlington, Vermont, completed North America's first transcontinental automobile crossing. Accompanied by a mechanic and a goggled bulldog named Bud, Jackson traveled 4,500 miles.

This excursion also took quite a while by today's standards: 64 days, over which time the trio drove on rocky pathways that could hardly be called roads and experienced just about every mechanical problem imaginable. It almost goes without saying that this trip, likewise, was no vacation.

But things were on the cusp of change as the Automobile Age was about to commence. An army of laborers began working overtime connecting the nation's cities with ribbons of blacktop.

The Great Northern Railway launched the "See America First" campaign. The campaign stoked fires that blazed into the country's modern obsession with cross-country travel.

In this article, you'll learn about the quirky, lively, amazing roadside attractions that came into fashion during the height of our nation's fascination with the Great American Road Trip, including:

Roadside Landmarks

Unique roadside landmarks dot America's landscape. From the iconic Hollywood sign to the lesser-known -- but equally delightful -- Corn Palace in Mitchell, South Dakota.

Roadside Statues

Superman stands guard over Metropolis, Illinois, while Hobo Joe casually greets visitors to Buckeye, Arizona. Statues both serious and whimsical pull travelers from the highways for a gander.

Roadside Architectural Wonders

See some of the world's most amazing architectural structures -- London Bridge, the Leaning Tower of Pisa, or the Eiffel Tower -- without a passport.

World's Biggest Roadside Attractions

From gigantic vegetables to tremendously-sized tires, explore the hotly-contested category of "world's biggest" in these pages.

Gas, Food, and Lodging Landmarks

A tip of the hat to the Old West, a tribute to an iconic burger boy, and a giant penguin make up just a few of the roadside attractions designed to bring folks in for a gallon of gas, a bite to eat, and a pillow on which to rest their heads.

Roadside Paranormal

When thinking about the cosmos, North Americans get imaginative. Learn about The Thing? in Benson, Arizona, or check out the UFO Landing Pad in Alberta, Canada.

Want to discover more family vacation destinations? See: