EXPLORERS
"Humans are exploring creatures. Some explorers have set sail across uncharted seas. Others have trekked across forbidding deserts or through dense jungles. Some have returned to tell their stories. Others have not. Some explorers are driven by the desire for wealth and fame. Others explore simply for the thrill of it. And still others explore to collect information about animals, plants, and people. . . "

PIONEERS
"History tells us that pioneers settled the American West. But history also tells us that people as diverse as John Glenn, Rosa Parks, and Christian Barnard are pioneers, too. So what, exactly, is a pioneer? According to one dictionary, a pioneer is someone who helps open up a new area of research or gives opportunities to others. So John Glenn would qualify as a U.S. space pioneer by being the. . . "

JEFFERSON
"Thomas Jefferson was a man of countless talents and interests. Best known for the many ways he served his country, Jefferson was one of the founders of the United States. He wrote our nation's first and perhaps most famous document - the Declaration of Independence. He served as governor of his home state of Virginia. He traveled to France to represent the new U.S. government, and in 1800, he . . . "

SACAGAWEA
"She is one of the most well- known, and unknown, figures in United States history. A river, two lakes, and four mountain peaks are named for her, but no one is certain how to pronounce or spell her name. Every child in the United States learns about Sacagawea (sa-CA-ga-we-a), but what does anyone actually know about her? We know for certain that in 1805 and 1806 she traveled with the Lewis and Clark. . . "