If you know the journal title you are looking for, start here. Always check with yor professor (in any course) for their recommended titles. For war propaganda research, you may want to start with:
The Journal of American History
The American Historical Review
Journal of African American History
The Journal of Interdisciplinary History
See all SHU History Databases or start with these:
* Use Advanced Search in Historical Abstracts and America: History and Life to search by era or date range. Scroll down to lower right corner.