Most of the colonies passed Acts authorizing the establishment of Post Offices under the provisions of the patent; and the principle of postal monopoly was introduced in these enactments.[138] The General Assembly of Virginia authorized a Post Office in the colony, believing such an office to be of "generall concernement and of great advantage for the increase and preservation of trade and commerce therein, for thereby speedy and safe despatch may be had."[139] The rates of postage were as follows:-- Every letter For distance not 3d. not exceeding exceeding 80 one sheet English miles Ditto two sheets " 6d. Every pacquet " 12d. per ounce of writs and weight. deeds Every letter Above distance 4-1/2d. not exceeding of 80 English one sheet miles Ditto two sheets " 9d. Every pacquet " 18d. per ounce. of writs and deeds The rates established in the other colonies were similar but not identical. The new postal service under the authority of the patent was commenced on the 1st May 1693. A post was set up from Portsmouth, New Hampshire, to Boston, Saybrook, New York, Philadelphia, Maryland, and Virginia. Five stages were fixed, and a rider was appointed to each stage. In summer the service was performed weekly, and in winter fortnightly. At the commencement, as may be readily understood, the conditions were somewhat difficult.[140] But with the growth of population and commerce, conditions improved. The service to the South was for many years subject to general irregularity and temporary suspension, especially at times of flood. The Post Office in America has from its first establishment as a general system, as distinguished from the merely local or municipal posts, had to reckon with two factors which have been of great importance in relation to all the main services--a vast extent of territory and a sparse population. The rates were higher than those in operation in England, but at first, and for many years, the revenue was insufficient to defray the expenses. The finance of the American Post Office consequently differed fundamentally from that of the English office.