I reviewed two of the eight books in this series and was very positively impressed. Although this series is advertised as an enrichment program, I can see it working very well for homeschoolers as an activities-based "spine" for a real books approach to U.S. History for junior and senior high students.
I'll begin with details about the books themselves. The titles of each book in the series tells you the time period covered in each:
Era of Exploration & Discovery
Era of Colonization & Settlement
Era of Revolution & Nation -Forming
Era of Expansion & Reform
Era of Civil War & Reconstruction
Era of Industrial Growth & Foreign Expansion
Era of Modernization Through the 1930s
Era of World War II Through Contemporary Times
Each book is self-contained with teacher material, student material, and answer key. There are five units in one book I reviewed and seven in the other, so I would expect something in that range for each of the other volumes.
Teacher material at the beginning of each unit briefly summarizes the key ideas of the unit then describes each of the student activities. Activities in this series often involve reading and completing reproducible worksheets with questions, charts, maps, etc. Sometimes they will require outside research, lengthier written responses, a hands-on activity such as creation of a poster or timeline, presentation of a speech, or participation in discussion. Usually these are not very time-consuming activities.
In addition to maps, charts, and other worksheets, within each unit are pages of background information that are to be copied and given to students since they don't have a textbook. (Yes, this does mean you will need to do quite a bit of photocopying, but you will only need the one book for your family or for a group class.)
The amount of information students read from these pages is relatively small, which should allow time in their school schedule to expand their knowledge of each time period by reading biographies, historical novels, and other real books. Lists of suggested books are at the back of each volume.
One thing I particularly like about this series is that questions and activities are thought-provoking. It presents a variety of viewpoints and pushes students to think beyond the obvious, look for cause and effect, analyze information, and generally go deeper than is required in most history courses. And because much of this happens through a variety of activities rather than the same type activity each time, it should be engaging for most students.
In the back of the book, following the answer key information for each unit, there are additional activity suggestions that I would highly recommend for high school students. For example, one suggestion from the unit covering the Declaration of Independence says, "Identify revolutions in other parts of the world that have been influenced by the Declaration of Independence." This one suggestion could become a research report or term paper.
Following these extra suggestions are some great assessment questions. These might be used for essay writing or oral discussion (great alternative for those who have difficulty writing).
The books were written for classroom use, so there are sometimes activities that suggest or even require a larger group. If you don't have enough children in your family, you might adapt or skip those activities, or you might consider working with another family or two to create a group class.
If you have a student who struggles with all the reading required in a typical textbook and needs a more interactive way to learn history, you might want to use this series of books as a stand alone resource. It's one of the few such series that I think would work in this fashion. The information is not "dumbed down" as you often find for struggling students. Instead the content has been condensed.
The books I reviewed were the second and third in the series. I did not spot any obvious religious or political biases or agendas in either book. I suspect the same will be true for the others, but I cannot say for certain.