The Marvel cartoons of the 80s cemented characters like Spider-Man in the minds of a generation of kids.
I've touched on it as part of The Big Picture, but what happened in U.S. children's television in the 1980s was a profound cultural shift that may in some ways be one of the most lasting and culturally-impactful legacies of the Reagan Administration.
Short version: As part of a broader trend of deregulation, the Reagan Administration ordered the FCC to relax laws that had discouraged and/or outright prevented children's television from being explicitly commercial in intent. A wave of series based on toys and other products flooded the airwaves... but not as many based on comics as you might imagine. Part of this was due to rules about human-looking characters not punching or kicking each other, robbing many traditional comic heroes of their main method of crime-fighting, but it was mostly business: DC and Marvel already had a medium for promoting toys based on their comic books -- their comic books.
However, Marvel was in the early stages of branching itself out into a broader multimedia company, and part of that strategy was absorbing and re-naming kiddie-TV/animation producers DePatie-Freleng Enterprises as "Marvel Productions." Their first big project: Build a loosely-connected (more through animation-style than story-continuity) Marvel Animated Universe jumping-off from DFE's New Fantastic Four and Spider-Woman cartoons discussed previously, starting with their biggest star...