1901
Leader Card Works was incorporated in the state of Wisconsin by Gustave A. Wilke and a group of fellow machinists. Leader Card Works specialized in the design and building of automatic machinery for the box and and paper converting trades. One of these original machines was designed to die-cut cards.

The first order for Leader's die-cut card machines fell through, and so as the "proud owner" of several unsold card manufacturing machines, Leader found itself in the card manufacturing business.

1903
Leader began to produce envelopes when a non-compete agreement between the owner of Leader Card Works and the United States Envelope Company finally expires.

1904
Leader negotiated a deal with United States Envelope Co., in which USE purchased Leader's entire inventory of paper and machinery for $20,869.24, but Leader retained all rights and licenses to the machinery design. Gustave and his associates became employees of USE and began designing envelope converting machines full-time while running Leader Card Works on the side. The company moved to a USE-owned facility in Waukegan, Illinois, where they stayed until they moved to Chicago in 1916.

1918
Leader returned to Waukegan after the US Government purchased Leader's Chicago building. Gustave became ¼th shareholder of Leader Card Works.

1920
Leader purchased a small building at 376-378 1st Avenue (currently 6th Street) and moved back to Milwaukee, to the same location where it is today.