For a mere six months in 1913, Parcel Postage Due stamps were required by law on packages bearing less than the necessary postage.
Before 1912, private companies controlled package deliveries throughout the U.S. Small towns were often overlooked in favor of more lucrative cities.
Effective January 1, 1913, the U.S. Post Office offered parcel delivery. Parcel Postage Due stamps paid the makeup fee for underpaid packages. At the end of six months, the Parcel Posts were replaced with ordinary postage stamps.