In addition to Collins and Gourdine, the original Imperials included Ernest Wright, Gloster "Nate" Rogers, and Tracy Lord, the last two of whom were subsequently replaced by Sammy Strain.

In 1957, a doo-wop group known as "The Chesters" was composed of Collins, Tracey Lord, Nathaniel Rodgers, and Ronald Ross.

Anthony Gourdine, a former member of The DuPonts, whose falsetto had been inspired by Jimmy Scott, joined as lead vocalist.

The line-up then became Collins, Wright, Sammy Strain, (a childhood friend who had grown up together with the Imperials in Brooklyn), and George Kerr.

With the help of record producer/songwriter Teddy Randazzo (a childhood friend of the group), the Imperials found success on the new DCP (Don Costa Productions) label with the dramatic pop-soul records "I'm on the Outside (Looking In)" (1964), "Goin' Out of My Head" (1964), "Hurt So Bad" (1965), "I Miss You So" (1965), "Take Me Back" (1965), "Hurt" (1966), "Better Use Your Head" (1966), and "Out of Sight, Out of Mind" (1969).

[4] In 1965, the Imperials appeared on the CBS-TV special Murray The K – It's What's Happening, Baby, where they performed "I'm Alright" before a live audience in New York at the Brooklyn Fox Theatre.

[5] At the height of their career, the group made two appearances on The Ed Sullivan Show, at the time television's top talent showcase, on March 28, 1965, and again on January 25, 1970.

Hullabaloo, Kraft Music Hall, Soul Train, American Bandstand, The Midnight Special, and The Tonight Show.

1992, the year of the group's reformation, was also the 40th anniversary of Dick Clark's American Bandstand, and he invited the Imperials to appear as part of the televised special celebration.

Also, during this period, they recorded two new CDs: Little Anthony & the Imperials – Live: Up Close & Personal (the group's first ever live album), and Pure Acapella,[12] an all a cappella CD showcasing the group's vocal talents on several classic 1950s doo-wop songs, including their own hit, "Two People in the World", which was written by Imperials member Ernest Wright.

[18] As of 2012[update], the Imperials were (along with the Dells), one of the few 1950s-era R&B groups still touring with the great majority of their original members (Gourdine, Collins, and Wright).

Little Anthony and the Imperials released their first new LP in several years in October 2008, entitled "You'll Never Know", and they performed on the Late Show with David Letterman on August 26, 2008.

The French electronic music duo Daft Punk sampled Little Anthony and the Imperials' 1977 recording of "Can You Imagine" for the track "Crescendolls".

[26] In early 2014, Gourdine toured the UK with David Gest's Legends of Soul, when he performed "Tears on My Pillow" and "Goin' Out of My Head".

When the group is not touring, Gourdine does stage plays and currently also has a one-man show, which he is currently doing to support his recently released biography, and to celebrate his 55-plus years as a performer.

[29][30][31] Over the decades, in a measure of their profound influence, several of The Imperials' hit songs have been covered by numerous other artists of many different musical genres, including pop, jazz, MOR, rock, Latin, country, doo-wop, and R&B.

Some examples: [41][42][43] In addition, according to songwriter and producer Kenny Gamble, Little Anthony and the Imperials and their music were a major influence in the development of Philadelphia soul, and artists such as the Stylistics, the Delfonics,[44] Blue Magic (who covered the Imperials' tune "The Loneliest House on the Block"),[45][46] Chicago's Chi-Lites, and other groups.

[47] They were also the first contemporary music group to play New York's prestigious Copacabana nightclub, even predating the Temptations and Supremes.

In October 2009, the group performed "Two People in the World" at the 25th Anniversary Rock & Roll Hall of Fame Concert.

[56] Sammy Strain is one of the few artists in popular music history to be a double Rock and Roll Hall of Fame inductee, having been inducted with the O'Jays in 2005 and the Imperials in 2009.