AUSTIN, Texas (CNN) -- Lady Bird Johnson, who was first lady during the 1960s and in her later years became an advocate for beautifying public landscapes, died Wednesday, family spokesman Tom Johnson said. She was 94.

Lady Bird Johnson's real name was Claudia. more photos »

She was the widow of Lyndon Baines Johnson, sworn in as the nation's 36th president on November 22, 1963, just hours after President John F. Kennedy's assassination.

Lady Bird Johnson was briefly hospitalized last month with a low-grade fever. She was released and returned to her Austin home on June 28. After suffering a stroke in 2002 that limited her ability to speak, she communicated chiefly by writing.

Upon news of her death, Texas Gov. Rick Perry ordered flags in the state to be flown at half-staff.

"Lady Bird Johnson embodied all that is beautiful and good about the great state of Texas," Perry said. "She inspired generations of Americans with her graceful strength, unwavering commitment to family and keen sense of social justice."

The former first lady was born Claudia Alta Taylor in 1912 in Karnack, Texas, a small town near the Louisiana line. She got her unusual nickname while still a toddler from her nurse, who proclaimed the child was as "purty as a lady bird."

Lady Bird attended St. Mary's Episcopal School for Girls, a junior college near Dallas and then transferred to the University of Texas at Austin. She graduated with a Bachelor of Arts in history in 1933, then stayed an extra year to earn a journalism degree.

She hoped to become a newspaper reporter, but those plans changed after she met a 26-year-old congressional aide named Lyndon Baines Johnson. Watch the former first lady's life in restrospect »

They married in 1934 after a whirlwind courtship and soon moved to Washington.

Early on, Lady Bird Johnson proved herself to be the quintessential political wife. In 1937 she used part of an inheritance to fund her husband's first bid for public office and campaigned with him to win a congressional seat.

She used more of her mother's money and Johnson's connections to purchase a faltering Austin radio station in 1942 for $17,500. She turned it around and later used the station as a base for a multimillion-dollar communications company based in Austin.

After three failed pregnancies, she gave birth to the Johnsons' first daughter, Lynda Bird, in 1944, followed by Luci Baines three years later.

Lyndon Johnson rose quickly in politics, becoming the youngest Senate majority leader.

In 1960, Johnson set his sights on the presidency but lost the Democratic nomination to Kennedy. A day later, he agreed to become Kennedy's running mate.

Lady Bird Johnson traveled more than 35,000 miles during that campaign.

After one of the closest presidential elections in U.S. history, Johnson was sworn in as vice president on January 20, 1961.

With Kennedy's assassination, Johnson became the 36th president.

As the Johnsons moved into the White House, Lady Bird Johnson "went around and went to all of the staff that was remaining in their jobs, told them how happy she was to have them there," said Leticia Baldridge, Jacqueline Kennedy's former social secretary.

"She needed their help. She needed their support. And, of course, they all just immediately turned from supporting the Kennedys to supporting the Johnsons. That's what the staff does in the White House."

In the landslide election of 1964, Lyndon Johnson won victories in the Northeast, West and Southwest. Of the eight Southern states that many had expected to vote for Republican Barry Goldwater, six went for LBJ -- in part, it was said, because of the first lady's efforts.

During her husband's one term as president, Lady Bird Johnson worked tirelessly for the beautification of America, promoting the Highway Beautification Act, which sought to limit billboards. She was also a strong advocate for the Head Start program.

Lyndon Johnson died in 1973.

In 1982, she founded the National Wildflower Research Center outside of Austin. The center was renamed the Lady Bird Johnson Wildflower Center in 1998. Its mission is the research and preservation of native plants throughout the United States. E-mail to a friend

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