LADY Bird Johnson, the widow of Lyndon B. Johnson, whose tumultuous presidency often overshadowed her considerable achievements as an activist first lady, environmentalist and founder of a multimillion-dollar media business, died Wednesday at her home in Austin. She was 94.

Johnson had been in failing health for several years, weakened by a series of strokes and other ailments, including a low-grade fever that kept her in the hospital for a week last month. A family spokeswoman said the former first lady's daughters, Lynda Johnson Robb and Luci Baines Johnson, were by her side when she died at 2:18 p.m. PDT.

As the wife of the 36th president, Johnson was often portrayed by contemporaries and some historians as a meek woman who silently endured her husband's volcanic outbursts and infidelities. Yet she, perhaps more than any presidential wife since Eleanor Roosevelt, expanded the terrain of the first lady by taking a visible role in her husband's administration, most memorably in her national beautification efforts.

Her love of nature was enshrined in law when her husband signed the Highway Beautification Act of 1965. Conceived primarily to restrict junkyards and unsightly signs along the nation's highways, it was the first major legislative campaign launched by a first lady.

Although often eclipsed by protests over the Vietnam War and civil rights -- the dominant issues of President Johnson's tenure from 1963 to 1969 -- her effort to replace urban blight with flowers and trees prepared the way for the environmental movement of the 1970s.

"I think there is no legacy she would more treasure than to have helped people recognize the value in preserving and promoting our native land," Luci Baines Johnson said in a statement shortly before her mother's death.

Johnson also broke new ground by campaigning independently of her husband. During the 1964 presidential campaign, she undertook a courageous whistle-stop tour of the South, where his civil rights agenda was widely reviled. Two months later, President Johnson won one of the largest landslides in U.S. history. She held the Bible at his swearing-in, a precedent followed by all her successors.

As her husband's key personal advisor throughout his career, she championed Head Start, the early childhood education program that was a major component of his War on Poverty, and was its first national chair.

She was deeply involved in his decision to run for his first full term in 1964, as well as in his dramatic announcement four years later that he would forgo a second term. His famous words -- "I will not seek, nor will I accept, the nomination of my party" -- were written by his wife.

Johnson often was compared unfavorably with her predecessor, Jacqueline Kennedy, who captivated Americans with an elegant style. Johnson did not wear designer clothes or introduce French chefs to 1600 Pennsylvania Ave., but she was the most active first lady since Roosevelt, her declared role model.

"Among first ladies of the 20th century, Lady Bird Johnson deserves to rank with Eleanor Roosevelt as one of the significant innovators in the history of the institution," presidential historian Lewis L. Gould once wrote.

Gould noted that Johnson assembled her own East Wing staff, which included the first officially designated press secretary for a first lady; participated in legislative strategy sessions; and personally lobbied for environmental programs.

As a businesswoman, Johnson had the foresight early in her husband's career to buy a debt-ridden Austin, Texas, radio station and parlay it into a broadcast empire eventually worth millions. She was, according to biographer Jan Jarboe Russell, the only first lady to have built and sustained a fortune with her own money.

Despite these accomplishments, Johnson was humble in her self-assessment. She told People magazine in 2000 that her greatest feat was "anything I did to keep Lyndon in good health and a good frame of mind to work as he did."

He was a moody man prone to depression who led the nation during a period bracketed by violence -- including the assassination of President Kennedy, the escalation of the war in Vietnam and the slayings of the Rev. Martin Luther King Jr. and Sen. Robert F. Kennedy. She defined herself as her husband's "balm, sustainer and sometimes critic" who soothed tensions in a besieged White House by relying on her keen instincts and sense of what was right.

It was she who made the conciliatory phone call or offered a dinner invitation after her husband had severely bruised a staffer's ego. It was she who set the tone after a top White House aide was arrested for a homosexual act by publicly expressing concern for the man's health and praising him as a dedicated public servant.

"If President Johnson was the long arm," her press secretary, Liz Carpenter, later wrote, "Lady Bird Johnson's was the gentle hand."

Lonely, shy child

Claudia Johnson