Scattered across the American Midwest and South are thousands of massive earthen structures. Some are shaped like animals, others rise like pyramids, and one is larger than the Great Pyramid of Giza. For centuries, European settlers refused to believe Native Americans could have built these sophisticated monuments, spinning wild theories about lost tribes of Israel, Welsh princes, and even Atlanteans.

The truth is far more fascinating: the Mound Builders weren't a single mysterious race, but multiple advanced indigenous civilizations. The Adena, Hopewell, and Mississippian cultures constructed these incredible earthworks over 5,000 years, creating vast trade networks, complex societies, and astronomical observatories. Cahokia, near modern St. Louis, was once larger than London with 20,000 residents. The Great Serpent Mound in Ohio stretches a quarter-mile long.

Join us as we explore America's forgotten ancient civilizations, uncover why their achievements were deliberately erased from history, and visit the mysterious mounds that still dot the landscape today. These silent witnesses reveal the sophisticated cultures that thrived in North America long before European contact. These aren't just piles of dirt. They're America's pyramids.

Keywords: Mound Builders, ancient America, Native American history, Cahokia, Great Serpent Mound, Hopewell culture, Mississippian civilization, Adena culture, earthworks, indigenous archaeology, American pyramids, prehistoric America, Ohio mounds, lost civilizations, ancient earthworks, Native American mounds