Final answer:
The controversial quote by John Lennon that impacted The Beatles' popularity in America was his assertion that The Beatles were 'more popular than Jesus'. This comment led to a significant backlash, including record burnings and radio bans, contributing to their decline in popularity and eventual breakup.
Step-by-step explanation:
The quote by John Lennon that caused a considerable controversy and can be associated with the end of The Beatles' popularity in America was his statement that The Beatles were 'more popular than Jesus'. This comment, which was part of an interview given to the London Evening Standard in 1966, was picked up by American media later that year. Lennon's remark didn't sit well with a predominantly Christian American public, leading to widespread backlash including radio bans and public record burnings. The controversy is seen as one of the elements that led to the band ceasing their touring and subsequently contributed to their break-up.
However, it's important to note that while this controversy had a notable impact, it wasn't solely responsible for The Beatles' decline in popularity or their eventual breakup. The late 1960s were characterized by a tumultuous political and cultural landscape, suggesting that multiple factors likely influenced the band's decision to stop touring and eventual dissolution.