Ten favorite unit studies from the archives:1. Free Nature Studies: Our Wonderful World 2. The Horse 3. The Oregon Trail 4. The Iditarod: A Unit Study 5. Winnie-the-Pooh 6. The Transcontinental Railroad 7. The Oklahoma Land Rush: A Unit Study 8. The Eiffel Tower 9. Laura Ingalls Wilder 10. Around the World in 80 Days: A Unit Study Ready for More?View all of our unit studies and book studies! You can also browse our units by date, in chronological order , or by subject.