#10A on cover from St. Louis to Cambridge MA - Superb postmark

The inner line on the left border is weak, but it is there. The St. Louis paid "3" circle town marking is listed in the Stampless Cover catalog. It was in use from 1851 to 1852. That fits nicely with the docking on the front, "Rec'd Dec 10, 1852."

The paper the envelope is made from is incredibly thin and light. Lower left corner was probably damaged by a mouse.