U.S. #1257, part of the third U.S. Christmas stamp issue, pictures Christmas conifer. The use of evergreens for trees and wreaths has long been a holiday tradition. America’s First Se-Tenant This third U.S. Christmas issue was unique in that it was the first time the Post Office had printed more than one stamp design on one sheet. Each block of four contains four different illustrations that were issued attached or “se-tenant.” This comes from the French term meaning, “to hold one another.”