Pop Art's own Wikipedia article documents its mid-to-late-1950s emergence and early-1960s rise to international prominence in detail, but states no explicit end date or point of decline anywhere in the article, and carries no "Years active" infobox field naming a close. Many art-historical surveys place a decline in the 1970s as the movement fed into Neo-Pop and Photorealism, but that describes a gradual evolution into successor movements rather than a documented end, and this atlas's own cited primary source does not state it.
What would resolve this A source naming a specific year or event as Pop Art's own agreed close, rather than an undocumented fade attributed to successor movements, would resolve this.
OpenArt HistoryWikipedia: Pop art