In general the answer is YES!
Pretty much every USMAI campus has a policy which allows unaffiliated users to use resources on-site. Obviously, they all have slightly differing implementations - guest logins, parking policies, etc.
For more information about using USMAI libraries in person, contact:
(p) (240) 895-3214
Conrad can either contact the library himself or put you in contact with the right person at the USMAI library you wish to visit.