They were the most successful American pop group of the 1960s—a group whose 12 #1 hits in the first full decade of the rock and roll era places them behind only Elvis and the Beatles in terms of chart dominance. They helped define the very sound of the 60s, but like fellow icons the Beatles and Simon and Garfunkel, they came apart in the first year of the 70s. The curtain closed for good on Diana Ross and the Supremes on January 14, 1970, at the Frontier Hotel in Las Vegas, Nevada.

The farewell concert in Vegas was the final act in a drawn-out breakup that didn’t become official until November 1969, but probably became inevitable in July 1967, when Motown Records chief Berry Gordy gave Diana Ross top billing over the Supremes. That move clearly signaled Gordy’s intention to launch Diana on a solo career—something he may have had in mind from the moment he upgraded her first name from “Diane” and upstaged her fellow Supremes by making Diana the group’s official lead singer.

Mary Wilson, Florence Ballard and Diane Ross grew up together in Detroit’s Brewster housing project and started out as co-equals in a singing group they called “the Primettes.” It took them several years of toiling within the hit factory Berry Gordy was assembling before the girls made their breakthrough in 1964. Those years included a Gordy-inspired name change for the group; a Gordy-mandated buffing and polishing in Motown’s in-house finishing school; and, eventually, a Gordy-dictated elevation of Diana over her childhood friends, Flo and Mary.

Yet even into early 1964, the group that would become Motown’s greatest commercial success was known as the “No-Hit Supremes” around Hitsville, U.S.A., the company’s Detroit headquarters. It was “Where Did Our Love Go”—a song written by the soon-to-be-legendary team of Holland-Dozier-Holland and rejected by the soon-to-be-eclipsed Marvelettes—that kicked off a run of success that saw the Supremes score an incredible five straight #1 singles in a 10-month span from July 1964 to May 1965. Five more #1s would come before Motown forced Flo Ballard out of the group she created, and two more would come with Cindy Birdsong as Ballard’s replacement before Diana Ross left the Supremes behind.