These websites contain useful collections of digitized materials. One challenge is you may not always be able to search them and have to browse.You can find research materials on educational websites. To narrow down the educational sites, you can search the education domain by typing site:gov in the search bar followed by the thing you are searching for.
This gives you content from colleges and universities that can supplement the materials you have locally.
The website for the U.S. Marine Corps History Division is not accessible at this time. Anyone needing historical information for the Marine Corps should contact history.division@usmcu.edu.