jewishvirtuallibrary:

Congregation Emunath Israel on West Twenty-third Street in New York, New York; 1944. x

On April 30th, 1944 the Synagogue Council of America called on all Reform, Conservative, and Orthodox synagogues in the United States to hold services when the invasion of Europe by the United States and the United Kingdom began.  On June 4th, 1944, when D-Day began, Jewish synagogues around the United States were open for 24 hours to allow people to pray for the success of the invasion and liberation of Europe from Nazi Germany.