This page contains information that will lead you to military-related resources that may be of help in your research.
We have accumulated some links here, including to "brick and mortar" research facilities and philatelic libraries.
Don't forget our own: Links to Other Philatelic and Military-Related Sites.
As an example of additional resources, the following links point to online groups and information about military-themed holiday cards. These links were discovered during the research for the original MPHS holiday cards web page group.
EBay (search for "greeting card soldier" or "antique greeting card military" for instance)
Vintage Postcards on Flickr (can also search Flickr site for military greeting cards)