There were mutliple printings of this adhesive, all made on Plate #6, with various shades of violet ink, ranging from light violet, through steel blue, red lilac, brown lilac and others. A total of ten million adhesives were printed and used. There are approximately 600 covers now in existence having one or more 24-cent adhesives still on them. The earliest known use of this adhesive was August 20, 1861. All covers being sent overseas were transported to several foreign exchange offices, notably New York, Boston, and others including San Francisco. These offices bagged the adhesives and arranged their transport on either British or U.S. packets but did send some mail by others.
During the later life of this adhesive, an attempt was made to prevent reuse by ‘grilling’ each adhesive. The process included running the sheet of adhesives through a field of small pointed spikes, which caused the adhesive fibers to tear allowing the cancellation ink to more fully penetrate the adhesive and thus make the cancellation ink less removable.
Siegel Encyclopedia (1857-60 Issue)
Civil War Timeline, at Siegel Encyclopedia