Written By: Ben Cosgrove

The only way to tell most New Year’s Eves apart is by the numbers that appear on the novelty hats and glasses. But December 31, 1941 was different. This was not long after the December 7 attack on Pearl Harbor, and America was finally, officially engaged in the world war that had begun 15 months before, when Germany invaded Poland. No one knew how long the war would last—but no one was betting it would be over soon.

And yet the party went on—in many ways the same, but it other ways clearly different. Here, LIFE.com remembers a wartime New Year’s Eve in a virtually unrecognizable New York City.

Times Square in New York City at midnight on New Year's Eve, as 1941 becomes 1942.

Times Square at midnight on New Year’s Eve, as 1941 became 1942.

John Phillips The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

Military police in Times Square on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

Times Square in New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

Times Square in New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

Partiers in New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

Partiers in New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

Partiers in New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

Partiers in New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Partiers in New York City on New Year's Eve, as 1941 turns to 1942.

Partiers in New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

Times Square in New York City on New Year's Eve, as 1941 turns to 1942.

Times Square in New York City on New Year’s Eve, as 1941 turned to 1942.

Gordon Coster The LIFE Picture Collection/Getty Images

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