If you are interested in American Quakers, this little book is a good place to begin your studies! Truly a pocket sized book, you can carry this with you everywhere. It is not the whole of John Woolman's journal, just some very good excerpts about this 18th century Quaker mystic and abolitionist who was strongly against slavery when other Friends had few objections.
Once you've read this, you may want to try his full sized Journal. This is a good book for beginners, for young people and for those who admire John Woolman but may not like to read a lot!