When you find your ancestor’s service records on Fold3, don’t forget to look at the Unit information.
If you browse into the Unit:
You will see Introduction and Unit Information. Click on Unit Information to see thumbnails of the record:
You will find summaries of who the leaders of the unit were:
As well as descriptions of when and where different units were during the war. Note, this isn’t a complete accounting, but it will give you a feel for what a specific unit was doing.
Remember the story about your ancestors is in the details, and the details are not always found in records about your ancestor but sometimes in records surrounding them.