Career
From 1872 until he died in 1934, Wolsieffer remained active in selling stamps, first in Philadelphia, Pennsylvania, and then in Chicago, Illinois. In 1914, he moved back to Philadelphia and purchased the Philadelphia Stamp Company which he renamed as P.M. Wolsieffer. From 1897 to 1933 Wolsieffer conducted 341 major auctions.
Wolsieffer was known for his invention of philatelic storage materials, such as the stock page (a slotted manila page used to temporarily store postage stamps) and the approval card, (a card with slots used to hold stamps), both of which he claimed to have invented.
He served the society in various ways, including as president and as vice president, and, because of his thirty years of dedicated work with the society, was named by the club as Life Member Number.