Consider the colon in bold, which is used to connect two sentences If it is not the best choice, replace it with a different punctuation mark. i Carousels were hugely popular amusement park attractions during the late nineteenth and early twentieth centuries : however, the onset of the Great Depression forced many of them to shut down.

The colon in the sentence is not the best choice because it is used to introduce a list, explanation, or elaboration, but here it connects two independent clauses. A semicolon would be more appropriate to connect these closely related independent clauses. Here is the revised sentence:<br /><br />Carousels were hugely popular amusement park attractions during the late nineteenth and early twentieth centuries; however, the onset of the Great Depression forced many of them to shut down.