sentences:  Essentially it meant that a postal packet was delivered from a post office to the addressee immediately once it arrived at the post office responsible for delivering it, rather than waiting for the next regular delivery to the addressee.The U.S. Post Office in conjunction with the Universal Postal Union established a basis for a special service for speedier delivery of mail for an extra fee beginning in 1885.Special Delivery was at first limited to post offices that operated in townships with populations of 4,000 or more.