Hi,
consider them just as logotypes and have a look at:
http://www.wikipedia.org/
Starting points could be:
http://en.wikipedia.org/wiki/United_States_Department_of_Defense
and the commons:
http://commons.wikimedia.org/wiki/Category:United_States_Department_of_Defense
bye bye
Does anyone know of a source, freeware or pay, for the logos for the branches of the us military--Marines, Navy, Army, Air Force, etc?