His Significant Other : MRS. IKE: Memories and Reflections on the Life of Mamie Eisenhower.<i> By Susan Eisenhower (Farrar, Straus & Giroux: 392 pp., $26)</i>

From childhood, Mamie Doud was treated like a princess. On her birthdays she would float downstairs in a party frock to the strains of “Here Comes the Bride.” Having seated her at the festive table, her father would bow. No wonder that four decades later Mamie Eisenhower seemed entirely at ease descending the White House staircase on the arm of the 34th president while a band played “Hail to the Chief.”

Her languidly imperious manner and large, if frumpy, wardrobe (she amassed more clothes than any other first lady) have caused her to be perceived almost as a caricature: the self-indulgent “Mrs. Ike” lazing all morning, playing cards all afternoon, smoking a lot and drinking even more. This perception has been further distorted by prejudice against a woman whose life’s ambition was simply to please her husband and to enjoy family and friends.

Difficult as it may be these days to portray such a person sympathetically, the task becomes doubly difficult if she was married to a man who achieved greatness in public life. But human character, multifarious as it is, has provided Mamie’s granddaughter, Susan Eisenhower, the chance to write a vivid and often poignant biography.

Drawing on recently discovered family papers as well as conversations with intimates, including Mamie herself, she is able to tell a richly factual and atmospheric story from a family perspective. No previous book in which Mrs. Eisenhower appears is as complete, certainly not J.B. West’s “Upstairs at the White House” (1973), Julie Nixon Eisenhower’s “Special People” (1977) or Lester and Irene David’s “The General and His Lady” (1981), which sets out to prove, quite convincingly, that Dwight Eisenhower did not consummate a rumored relationship with his wartime driver and clerk, Kay Summersby. In “Mrs. Ike: Memories and Reflection on the Life of Mamie Eisenhower,” Susan Eisenhower, too, dismisses the scandal on ample testimony that Ike, though often bereft of close companionship, was a scrupulously monogamous man.

Mamie (not a nickname) Geneva Doud was the second of four daughters, born in 1896 to John and Elvira Carlson Doud, in Boone, Iowa. The Carlsons were mill owners of Swedish ancestry, while the Douds, originally from England, ran a meatpacking business. By the time John was 36, he was a semi-retired millionaire and indulgent father.

At age 7, Mamie had rheumatic fever, which left her with damaged heart valves. As a result she was, by her own admission, “rotten spoiled.” She was also a poor student. After a sporadic elementary education and one year at finishing school, she made her debut. By then the Douds had moved to Denver and were wintering in San Antonio, Texas. It was there, one December day in 1915, while visiting friends in nearby Fort Sam Houston, that 19-year-old Mamie first laid her china-blue eyes on West Point graduate Dwight David Eisenhower. Ike, then almost 25, was the officer assigned to inspect guard posts when someone beckoned him over to meet a milky-complexioned, brown-haired girl, beguiling in pink crepe de Chine. He recalled that she was vivacious, “smaller than average, saucy . . . in her whole attitude.” Intrigued, he asked her to complete his tour with him. She agreed to go, thinking him “the handsomest man” she had ever met.

An instantaneous courtship ensued and father Doud, seeing that they were “wild about each other,” agreed to a July 1916 wedding. Early married life in cramped Army quarters was hard. Little was left each month of Ike’s $167.67 salary. The Douds held off on giving financial help and Mamie never contemplated taking a job. “I have but one career,” she said, “and its name is Ike.”

In September 1917, Mamie gave birth to a boy nicknamed “Ikky,” but he died of scarlet fever three years later. “This was the greatest disaster in my life,” Ike would write unequivocally in old age. Only work distracted him, and it took the birth of another son 19 months later to raise Mamie’s spirits--that and the challenge of another locale. The Eisenhowers were to move some 35 times in as many years, as Eisenhower rose steadily through the ranks of the Army, staying on nine bases and living in suites in the Manila Hotel, in Washington apartments, French mansions and a New York townhouse.

This gypsy existence increased rather than lessened their domestic closeness, making it inevitable that while he was in Europe from 1942 to 1945, supreme commander Eisenhower would feel desperately lonely. (Of America’s four five-star generals, only Ike spent the war years without his spouse.) During their separation, rumors of Mamie’s drinking spread. It is probably true that she took more than her habitual single old-fashioned at canasta and mah-jongg parties, as did other solitary Army wives. But after Ike returned she drank little hard liquor. What people assumed to be signs of inebriation, writes Susan Eisenhower, was actually a periodic loss of balance caused by Meniere’s syndrome, a viral ear infection that was not diagnosed until 1953. “She had complained of a ‘pitching’ sensation in the Philippines. But . . . the problem worsened,” the author writes.

During the White House years, Mamie therefore did most of her clerical chores in bed, answering a half-million letters in eight years. She also made phone calls, planned menus and consulted with her staff before rising in time for her favorite mid-day television soap opera. Dressing well for Ike was one of her top priorities. She once warned her prospective daughter-in-law that “tired bedroom slippers and runover heels were a sure way to lose a husband.”

After Ike died in 1969, Mamie lived on for 10 years in the only home they ever owned, a farm in Gettysburg, Pa. At night, she would touchingly pile up books, boxes of stationery and tins of sweets beside her where Ike used to sleep, hoping to mitigate the pain of his absence. A few months before her death, she wrote a childhood friend, “I’m still that little girl skating up and down the sidewalk.” By then, having already suffered several small strokes, she quietly set aside the gown in which she wanted to be buried. It was the one she had worn for her 50th wedding anniversary.

Mamie Eisenhower’s main goal was perfecting the life she shared with the man she adored. He, loving her no less, strived for perfection in his work. In this he had the ideal partner. Gen. George Patton once said that for a woman to like Army life she must be “narrow-minded, not over-bright, half-educated.” Was Mamie then the girl Lt. Eisenhower should have left behind? Ike never thought so.