It all seemed so predictable. The news that the heir of the Rockefeller fortune was marrying the daughter of a prominent Rhode Island senator made headlines in the fall of 1901. But Abby Aldrich, the bride, had more than a fairy-tale marriage in mind. "She was so gay and young and so in love with everything," said her smitten husband, John D. Rockefeller Jr. -- inadvertently emphasizing the features that made her decidedly un-Rockefeller. Armed with boundless enthusiasm, Abby took on the challenge of changing her new family from within. She would do that in profound and subtle ways, softening the Rockefellers’ rigidity and helping them to embrace the modern world.

Born in 1874 in Providence, Rhode Island, Abby Aldrich grew up in a well-to-do milieu, but one quite different from that of her future husband. Her father, Nelson Aldrich, was a senior Republican senator and a leading power broker in Congress. In contrast to the reclusive Rockefellers, the Aldriches were gregarious and well traveled. From an early age, Abby was exposed to a stimulating life rich in politics, art, literature and society. She emerged from it a self-confident woman, outgoing and curious, with a strong personality.

It was these qualities that drew the attention of John D. Rockefeller Jr. when he met Abby in Providence in 1894 when he was a sophomore at Brown University. After a courtship that lasted five years, the couple was finally married at a lavish wedding ceremony on Warwick Neck, Rhode Island on October 9, 1901.

John’s devotion to Abby and her ability to appreciate his strengths in turn would nurture an intense relationship that was able to withstand their differences. She found creative ways to stretch the rigid boundaries imposed by her husband —- and deal with his almost obsessive jealousy, which extended to their offspring. She would telephone the children from the bathroom, and use her diplomatic skills to make up for his aversion to socializing.

Abby would have the strongest influence on the couple’s five sons. A playful and attentive parent, she encouraged them to have an interest in the larger world and instilled in them her open-mindedness. "I want to make an appeal to your sense of fair play … to begin your lives by giving the other fellow a fair chance and a square deal," she wrote in a 1923 letter to John III, Nelson, and Laurance about the rise of racism, an issue most white Americans chose to deny or ignore at the time. "It is to the everlasting disgrace of the United States that horrible lynchings and brutal race riots frequently occur in our midst. The social ostracism of the Jews is less barbaric, but … causes cruel injustice… I long to have our family stand firmly for what is best and highest in life… If you older boys will do it the younger will follow."

Abby’s progressive ideas led her to a variety of philanthropic causes, from the YWCA to Planned Parenthood. She was a dedicated and knowledgeable donor in her own right, finding her distinctive path in the field chosen by her husband.

She also developed an interest in modern art, an avocation she would pass on to her son Nelson. "She was attracted by the unusual, adventurous, inner directed art," says biographer Bernice Kert. "She liked experimentation, she was open to new ideas, and also she wanted to understand the art that her children would grow up to understand. In other words, she wanted to be a modern."

But modernity -- at least in art -- was not John D. Rockefeller Jr.’s forte. Abby’s enthusiastic support of the work of artists like Matisse, Rivera, Van Gogh, and Chagall was a source of friction between her and her husband. He strongly objected to her involvement in a new museum that would make such "unintelligible" art available to the public. Abby went ahead anyway and, in 1929, co-founded the Museum of Modern Art (MoMA) with friends Lillie P. Bliss and Mary Quinn Sullivan. "Mother’s museum," as it would be known within the family, was the first in the country to devote its collection entirely to the modern movement, and now houses more than 100,000 works.

Abby’s commitment to the new would be felt even after her death in 1948. Based on her will, some of the valuable impressionistic works she had originally donated to MoMA were transferred to other museums in 1998. The foresighted arts patron believed that, after half a century, they would no longer be "modern."

For generations of Rockefellers, Abby has always been a lot more than just the family’s matriarch. "For her to have accomplished what she did must have seemed really amazing at the time," reflects grandson Rodman Rockefeller. "She lifted us from a fairly narrow definition of life to a lot more fun in life, at the same time keeping this very constructive sense of obligation … this sense that there are things to be done and worlds to conquer and places to make improvements."