Early United States stamps bearing postmarks—oftencalled "town" cancellations—with year dates are scarceand much sought after. In fact, any unusual cancellationon a stamp is a collectable item.
In addition to the postmark and the killer the PostOffice often used other marks upon stamps and letterswhich are of interest to collectors. The stamps on allforeign addressed mail that passed through the NewYork Post Office from 1871 to 1877 were canceled witha killer in the shape of fancy stars and designed usuallyin a circle. There are about one hundred different typesof these New York foreign mail killers and all are eagerlysought after.