How did one-line jokes change the relationship between cartoon drawings and captions?

The rise of the one-line joke, largely pioneered or reinvented by The New Yorker starting in 1925, fundamentally transformed the relationship between cartoon drawings and their captions.12

Prior to this shift, cartoons often relied on "five-decker dialogues" with headings, which were cumbersome and cluttered. The introduction of the one-line joke swept these away, creating a greater unity between the image and the text. This evolution paralleled broader trends in media, such as the move toward tabloid-style journalism that favored pithy, concise text alongside large photographic halftones.1

By integrating the caption more tightly with the visual, the comedy-of-manners cartoon shifted its focus. The burden of conveying the joke moved away from wordy explanations, plays on words, or marked action, and instead relied more heavily on the cartoon's costume, setting, and situation. This change emphasized the "cartoon of situation," where the humor is derived from a specific predicament or ludicrous detail rather than a complex, multi-line dialogue. In some cases, this integration became so effective that the situation was clear enough to render even a single line of text unnecessary.1