Washington still cherishes a belief that it was long a place of bipartisan comity, of after-hours socializing during which fences were leapt and mended and the gears of the republic were lubricated with alcohol and bonhomie. There is an element of truth to the legend. Until the late nineteen-fifties, all U.S. senators occupied a single Senate Office Building, affectionately called the S.O.B. They saw a lot of one another. But, as they and their ever-growing staffs spread out over Capitol Hill (they’re now in three different buildings), senators became less likely to R.S.V.P. in the affirmative to any Washington social invitation. As Neil MacNeil and Richard A. Baker point out in their 2013 history of the Senate, “Since the 1960s, with the greater availability of high-speed jet aircraft, senators have found it convenient—or politically necessary—to return home at least weekly,” not only to raise money but also to see their families, whom they often no longer bring to live in the capital.

Allen Drury’s “Advise and Consent,” still the most famous of Washington novels, was published in 1959, on the cusp of the changes MacNeil and Baker describe. The book features a hostess named Dolly Harrison, her first name probably an homage to both Dolley Madison and Dolly Gann, a Washington hostess of the twenties and thirties. But some of Drury’s Dolly is a toned-down Perle Mesta, the capital’s most famous mid-twentieth-century party-giver. Readers are told that in Dolly’s “great white house amid the dark green trees”—an image that resembles Mesta’s mansion—“more than one crisis has been solved.” In her 1960 autobiography, “Perle: My Story,” Mesta tells a tale that fits in with the productive fraternizing Drury portray

Once I invited Senator Alexander Wiley and the late Senator Pat McCarran to a dinner party, knowing perfectly well that they were not even on speaking terms. I had seated Senator Wiley at my right and Senator McCarran at my left. During the first course, Senator Wiley leaned toward me and whispered in his gentle way, “Why have you got that McCarran here?” Before long, Senator McCarran nudged me and said, “What in hell have you got Wiley here for?” For a while things remained pretty frigid. Finally I looked straight ahead and said good and loud so that I could be heard the length of the table, “Well, Perle, I guess you’ll just have to talk to yourself all evening.” And do you know?—at the end of the evening those two men left the house arm in arm.

Nasty little scenes were not unusual at Evalyn’s on those Sunday nights. She thought it dull and unproductive of social excitement to have a table of guests who always agreed with each other, and instead preferred to seat at the same table an isolationist reactionary senator and a liberal interventionist and then to stand back and wait for the screaming arguments. . . . At times, to Evalyn’s pleasure, a guest would rise from the table red in the face, fling down his napkin and stalk out.

Reality aside, it is Perle Mesta, not Evalyn McLean, whose name is still remembered, albeit a bit dimly, fifty years after her death. With political loyalties that oscillated between Republicans and Democrats, Mesta was not especially interested in amassing Washington’s usual currency, power. It was notice that she wanted, and she achieved an everlasting degree of it as “the hostess with the mostes’, ” Ethel Merman’s character in Irving Berlin’s Broadway musical “Call Me Madam” (1950). Mesta didn’t run a salon; she threw soirées. As Meryl Gordon explains in her new biography, “The Woman Who Knew Everyone” (Grand Central), “Perle wanted her guests to unwind and enjoy themselves, to look forward to seeing new entertainers and surprise performers.” Sam Rayburn, the Speaker of the House, called her Perly-Whirly. She sent her guest lists to the society pages of the city’s newspapers, and then invited the reporters themselves.