When was the crossword puzzle invented?

December 21, 1913

Explanation:

The first known published crossword puzzle was created by a journalist named Arthur Wynne from Liverpool, and he is usually credited as the inventor of the popular word game. December 21, 1913 was the date and it appeared in a Sunday newspaper, the New York World.

In December 21, 1913, the first known published crossword puzzle was created by a journalist named Arthur Wynne from Liverpool