What does made in Germany us zone mean on shot glasses?

"Made in Germany U.S. Zone" marks items produced during the post-World War II Allied Occupation. After defeat, Germany split into occupation zones divided among the Allies.

As part of the occupation by the United States, there was a U.S. Zone where production marked goods as "Made in Germany U.S. Zone" to comply with military-industrial controls put into effect during World War II. Eventually, Germany was divided into East Germany and West Germany.