Eleanor Roosevelt -- niece of one president and wife of another -- was a shy woman who overcame her homely appearance and personal insecurities to become one of the nation's best politicians and social activists.

Her story, the first profile of a first lady to air on PBS's "American Experience," launches the series' 12th season Monday at 9 p.m. The portrait is from producers Kathryn Dietz and Sue Williams; Williams also directed and wrote it. Alfre Woodard narrates.

Like her husband and distant cousin, Franklin Delano Roosevelt, Eleanor Roosevelt (1884-1962) came from aristocratic stock but was a lonely child. Her beautiful mother, Anna, a socialite, despaired over her homely daughter, sometimes calling her "Granny." She died when Eleanor was 8. Her father, Elliott, the older brother of Theodore, doted on her and called her "Little Nell," but he was an erratic, irresponsible alcoholic who was considered unfit to care for his three children and died when Eleanor was 10.

Her maternal grandmother sent the orphaned Eleanor to an English boarding school, where she flourished. On her return to New York, she began working in a settlement house in the Lower East Side, made her social debut and resumed a friendship with Franklin. When he was 20 and she 21, they married, producing six children within 10 years.

Then, in 1918, Eleanor learned that he was having an affair with her secretary. Angry, she offered him a divorce, but agreed to stay with him at the behest of his mother. Stricken with polio in 1921, he nevertheless ran for and was elected governor of New York in 1928 and president in 1932, the first of four terms.

They continued as friends, but Eleanor began to change her life. Having been disappointed in the two men she had loved, her father and husband, she carved her own agenda. She took positions that sometimes generated controversy, wrote a daily column ("My Day") and magazine articles, did radio commentary, gave lectures, held press conferences.

She also became a social and civil-rights activist, positions that sometimes made her unpopular and resulted in death threats. At one point, she wrote: "Every woman in public life needs to develop skin as tough as rhinoceros hide." Apparently she did. Historian Geoffrey Ward calls her "tough as nails, one of the best politicians of the twentieth century."

And Eleanor began to build other relationships. One was her friendship with Lorena Hickok, a lesbian. Others involved at least three men: a New York state trooper who was her bodyguard, a physician 20 years her junior, and a student leader of the American Youth Congress (which resulted in a whopping 3,000-page FBI file).

Political cartoonists could be cruel, finding her appearance easy to caricature, but in 11 consecutive Gallup polls Americans ranked her as the most admired woman in the world. After FDR's death in 1945, she became the U.S. representative to the United Nations, working to win passage in 1948 of the Universal Declaration of Human Rights.

The documentary offers rare home movies and voice recordings, as well as recollections from her friends and relatives, including four grandchildren.