Lady Bird Johnson died of respiratory failure yesterday at the age of 94.
Lady Bird Johnson will be buried on Sunday
The former US first lady, a quiet but powerful adviser to President Lyndon Johnson, was one of the last major figures from the Great Society era of the 1960s, when she campaigned for her husband's civil rights, environmental and anti-poverty policies while promoting her own pet cause of beautifying America.
She had been in declining health since a 2002 stroke that left her unable to speak.
Following a private funeral on Saturday, Lady Bird will be buried on Sunday beside her husband at the family cemetery on the LBJ ranch west of Austin, Texas.
Lyndon Johnson died in 1973 of a heart attack, four years after leaving office.
Lady Bird was at her husband's side as he came under fire for escalating the Vietnam War and supported his decision not to seek re-election as president in 1968.
Claudia Alta Taylor was born in Karnack, Texas, near the Louisiana border in 1912. She was two years old when she was given her nickname by a maid who described her as "purty as a lady bird".