“Commemorating the 300th anniversary of printing in America, this stamp features Stephen Day’s printing press, the first press used in the American Colonies. Stephen Daye was a printer in England who emigrated to the Massachusetts Colony in 1639 and set up a printing press at Harvard College. There is some debate amongst scholars as to the first printed document in America, but most agree that it was either The Freeman’s Oath, a broadsheet (similar to a newspaper page) or William Pierce’s Almanac. Both were printed by Daye’s press, so either way his press was the first in America. A year later, the first actual book was published in America, the Bay Psalm Book by Daye on the same press.”
Here is a commemorative cover mailed to Vallejo, California.