Philadelphia did not use a "P" mintmark until 1980. Before then, the absence of any mintmark indicates Philadelphia. (Exception: silver alloy nickels 1942-45.)
Цитата: "Cerulean"Philadelphia did not use a "P" mintmark until 1980. Before then, the absence of any mintmark indicates Philadelphia. (Exception: silver alloy nickels 1942-45.)
Yes, you beat me to it.
American catalogues like to say "1943 P" (for example) for distinguishing the Philadelphia issues even before the P mintmark became commonplace.