The 1960s version of the group included Frank Sinatra, Dean Martin, Sammy Davis, Jr., Joey Bishop, Peter Lawford, and for a brief stint, Norman Fell. Marilyn Monroe, Angie Dickinson, Juliet Prowse, and Shirley MacLaine were often referred to as the "Rat Pack Mascots", a title which reportedly made these ladies feel like "one of the boys". The post-Bogart version of the group (Bogart died in 1957) was reportedly never called that name by any of its members — they called it the Summit or the Clan. "The Rat Pack" was a term used by journalists and outsiders, although it remains the lasting name for the group.
Often, when one of the members was scheduled to give a performance, the rest of the Pack would show up for an impromptu show, causing much excitement among audiences, resulting in return visits. They sold out almost all of their appearances, and people would come pouring into Las Vegas, sometimes sleeping in cars and hotel lobbies when they could not find rooms, just to be part of the Rat Pack entertainment experience. The marquees of the hotels at which they were performing as individuals would read, for example, "DEAN MARTIN - MAYBE FRANK - MAYBE SAMMY" as seen on a Sands Hotel sign .
Peter Lawford was a brother-in-law of President John F. Kennedy (dubbed "Brother-in-Lawford" by Sinatra), and the group played a role in campaigning for him and the Democrats, appearing at the July 11, 1960 Democratic National Convention in Los Angeles. Lawford had asked Sinatra if he would have Kennedy as a guest at his Palm Springs house in March 1963, and Sinatra went to great lengths (including the construction of a helipad) to accommodate the President. When Attorney General Robert F. Kennedy advised his brother to sever his ties to Sinatra because of the entertainer's association with Mafia figures such as Sam Giancana, the stay was cancelled. Kennedy instead chose to stay at rival Bing Crosby's estate, which further infuriated Sinatra. Lawford was blamed for this, and Sinatra "never again had a good word for (him)" from that point onwards. Lawford's role in the upcoming 4 for Texas was written out, and his part in Robin and the Seven Hoods was given to Bing Crosby.
On June 20, 1965, Sinatra, Martin, and Davis, with Johnny Carson as the emcee (subbing for Bishop, who was out with a bad back), performed their only televised concert together during the heyday of the Pack at the Kiel Opera House in St. Louis, a closed-circuit broadcast done as a fundraiser for Dismas House (the first halfway house for ex-convicts). Thirty years later Paul Brownstein tracked down a print of the "lost" show in a St. Louis closet. It has since been broadcast on Nick at Night (in 1998) as part of The Museum of Television & Radio Showcase series  and released on DVD as part of the Ultimate Rat Pack Collection: Live & Swingin.