What a great way to introduce or review the 1920s in American History! I use this to start my unit on the Roaring Twenties in my on-level US History course for sophomores/juniors. Students begin the activity by solving a cryptogram which gives them the words to find in a word search. The letters that they have left in the word search spell a secret phrase. They will then use the words from the cryptogram to complete a crossword puzzle.
I give students one class period to complete this assignment and then give the rest for homework. However, you can probably spend 2-3 days on it if you would like.