The promise of America is that the country is based on an idea, one where everyone is created equal and equally free to chart their own course. From 13 newly independent states ratifying a national constitution to the heated debates in the halls of Congress today, American politics is about negotiation over what our country is—and where we are going.

Many Americans remember a family road trip to visit one of our 63 national parks. Why did Americans start preserving these sites of natural and historic interest? How were these parks selected, and what steps did conservationists, activists, philanthropists, politicians, and others take to protect millions of acres against the booming developments of an expanding nation? An award-winning writer, researcher, and American Studies scholar, Dr. Megan Kate Nelson tackles these questions as she takes you on a marvelous journey through some of the most beautiful places on Earth.

The history of the Constitution is therefore a history of ideas that define our country and our national identity—and it’s a fascinating and revealing story. The US Constitution Through History gives you the opportunity to explore the story of this powerful document, as well as the way our interpretation of it has evolved. In 24 riveting lectures, Professor Eric Berger of the University of Nebraska takes you on a journey through America’s constitutional history. He takes you inside the minds of the Framers and unpacks the ideas that led to the break from England.

“Who are you?” Chances are you’d answer this question by describing the highlights of your personality and life experiences. But if you’d been asked this same question yesterday, you might have responded with a slightly different description. Does that mean you are a particular person today but were a different person yesterday? And what about tomorrow? Welcome to the slippery, shape-shifting nature of memory. As Professor Gabrielle Principe reveals, “you” are the conglomeration of the often-unreliable information your brain decides to feed you at any given moment.

Heidi Sormaz has a PhD in psychology from Yale University with an emphasis on cognitive psychology, and she’s been a meditation and yoga practitioner and teacher for two decades. She is also a reformed over-thinker, so, she knows exactly what you’re going through—or what you’re (over)thinking, so to speak. Over the 12 engaging lessons of Overcome Your Overthinking, Heidi not only provides the science behind cognitive behavioral therapy but she’ll also arm you with a toolbox of exercises and techniques that are most effective at breaking the spell of overthinking.