Stephanie,
I am not Julie but we did use Adventures a few years ago and are now using Sonlight 3&4. We did Adventures when the boys were 7 and 9 and it was perfect for those ages. A bried overview of US history, not too detailed, cute hands on projects etc... My boys are 10 and 12 now and doing Core 3&4 and some of the read alouds stretch my 10 year old, so 8 might be a little young for Core 3. It is a wonderful Core though and defenitely one to keep in mind later on!
HTH!