In a somber ceremony today, President Joachim Gauck called the attempted assassination on July 20, 1944, a "significant day in German history."
Hitler survived the bomb attack and was able to continue his military campaign to conquer Europe and eradicate the continent's Jewish population for another year.
Four officers including Claus Schenk Graf von Stauffenberg were executed without trial. Some 200 supporters were killed later or driven to suicide.
Gauck said the conspiracy, recently portrayed in the Hollywood film "Valkyrie," showed the world that there was a "different Germany" than that of Hitler's regime.