Like almost everything else governments printed for public consumption during the war, postage stamps, in all their variety, were designed to stoke patriotism.

There’s no mistaking the patriotic message on the standard three-cent US postage stamp of World War II.

The army, navy, marines and coast guard were all honored with stamps during the war. The merchant marine, which served gallantly at the cost of thousands of lives, got its recognition in February 1946.

Other nations used postage stamps as a medium to deliver war messages and imagery. This Canadian 50-cent stamp depicts the manufacture of artillery.

The Overrun Nations series of US stamps were printed by the American Banknote Company with a full-color flag inset. This series was the only time foreign flags have been honored on US postage stamps. About 20 million each of the Poland, Czechoslovakia, France, Belgium, Netherlands, Luxembourg, and Norway stamps were printed. Fifteen million Denmark, Austria, Albania, Korea, Yugoslavia, and Greece stamps were issued.

Norway was the third country the Nazis invaded. British and French troops unsuccessfully opposed the April 1940 invasion.

A five-cent Overrun Nations stamp honored Belgium, occupied during the German blitzkrieg of May 1940. On the left of the flag is a phoenix, rising from the flames of its own destruction. On the right is a captive breaking her chains.

Including Austria in the Overrun Nations series was a sly bit of Allied propaganda. Austria, which had been annexed by Germany in 1938, was enthusiastically part of the Reich during the war.

The little duchy of Luxembourg was overrun in the Nazi offensive of May 1940.

The Netherlands was another nation overrun by the Germans in 1940. There is some question if the printing quite captures the Dutch orange in the top bar of the tricolor flag.

The kingdom of Yugoslavia was invaded by the Germans and Italians in April 1941. This was in response to Yugoslavia’s rejection of an agreement to join the Axis announced the month before.

This four-centavo stamp was used in the Philippines before the 1941 Japanese invasion. The Japanese continued the use of the stamps—with an overprinting to indicate who was in charge now.

The US government made a high priority of getting the GI vote counted in 1944. Air mail was a separate—and expensive—category of postage in those days. The government ate the expense and filled aircraft cargo holds with soldier and sailor ballots.

Postcards were a good medium for government propaganda or, in this case, some gentle service-related humor. This was about as extreme as the Post Office would allow back in the 1940s.

Here is another gag postcard from the early war years. The non-propaganda message is “Boys will be boys.”

The idea of putting war propaganda on privately sold mail envelopes goes all the way back to the Civil War. This WWII example depicts the Allies’ victory train about to run down Mussolini, Tojo, and Hitler.

Servicemen enjoyed free postage throughout the war. All a soldier or sailor had to do was write “Free” on the piece and the Post Office would deliver it. Even if a soldier wanted to mail the end of a C rations box as a postcard, the Post Office would deliver it.

Soldier mail and international mail was routinely checked by censors to ensure that vital war information was not passed along to unauthorized persons. An Australian’s fan letter to Bob Hope got the treatment.

Young and old could affordably assist the war effort by buying US Savings Stamps, which would apply to the purchase of larger denomination War Bonds. A model demonstrates, in a saving stamp sun suit, what an attractive investment the stamps could be.

During the war, civilian charities had to compete to get their share of charitable giving. The American Lung Association relied on Christmas Seals—like these 1943 examples—to fund its battle against tuberculosis.