1. Combine thawed orange juice and marjoram in small bowl. Pour 1/2 oj mixture into the slow cooker.
2. Add chicken to pot.
3. Use tongs to coat each piece of chicken well with oj glaze, using more oj glaze if necessary.
4. Pour remaining oj mixture on top of breasts.
5. Cover; cook on LOW 7-9 hours, or HIGH 4-5 hours.