Unlike COLE 2.0/Moodle, once a course term ends, the course goes into "Archived" status in COLE 3.0/Schoology. It doesn't go away, but it isn't available via the drop-down list any more. A teacher can still access the course by going to "See all" under the Courses drop-down and then clicking on the "Archived" tab in the "My Courses" listing. Students and parents, though, cannot access the course once it's been placed in the Archived area.
In any course, a teacher can use the "Options" pull-down to get to the "Save Course to Resources" option. If a teacher wishes to save the course content to a group for sharing with others, s/he can just select the Group as the destination. After choosing a destination, a folder will be created in that location with all of the course content inside.
As we continue with the school year, it's best to build content in the Resources area instead of a course as it simplifies this issue and makes copying to other courses or sharing with others much easier.