TEMPORARILY CLOSEDOpen every day (except December 25)
10:00 am to 5:30 pm
Admission is always free!
2 Massachusetts Ave., N.E.
Washington, DC 20002
After the invention of stamps, handstamps were used to cancel the postage and guard against their re-use. Though this initial function has never changed, handstamp markings have changed over time to provide more information.