The Tuskegee, Ala., native, who in 1999 received the nation's highest civilian award, the Congressional Gold Medal, died in Detroit, where she had lived since 1957. Parks died at home of natural causes, said Karen Morgan, a spokeswoman for Rep. John Conyers, D-Mich.
Over the years, Parks spoke to scores of student, civic and church groups, gave dozens of interviews, received countless awards and saw streets, schools and rap and pop songs named after her.
"Surely Mrs. Rosa Parks was sent to us by God, because few among us were so well prepared to play such a momentous role in history," said Coretta Scott King, widow of civil rights leader Martin Luther King Jr.
In 1999, Time Magazine named Parks one of the 100 most important people of the 20th century. She even has an entry in an edition of Bartlett's Familiar Quotations, 13 pages away from the infamous "Segregation now" remarks in former Alabama Gov. George Wallace's 1963 inauguration speech.
But Parks was not a prominent civil rights leader and never sought to be one. During the era in which she was in the spotlight, there were other key events -- such as the U.S. Supreme Court's 1954 Brown decision outlawing public school segregation -- that helped start the drive to overturn the pervasive discrimination besetting black Americans.
Also, long before Parks' arrest, black leaders in Montgomery had been looking for the opportunity to launch a boycott. But women who had faced the same mistreatment that Parks faced were not deemed to be suitable candidates around whom to organize a protest.
Still, historians and analysts consider Parks' quiet act of defiance on Dec. 1, 1955, to be the civil rights movement's major catalyst. It led to a highly effective mass protest and a successful court challenge of Alabama segregation laws. And, in Alabama and elsewhere, it gave blacks additional confidence that the system could be changed. It also led to the emergence of the civil rights movement's most influential leader, Martin Luther King.
At the time of her solitary protest, Parks had been working as a tailor's assistant in the Montgomery Fair department store and would ride a city bus to and from her downtown job. For most of the time she rode the bus, black passengers had to sit in the back. Often, when they bought their tickets at the front of the bus, they were then obliged to step outside and board through a rear door. Once, Parks said, she had been ordered off a bus for refusing to reboard it from the rear.
Whites, meanwhile, sat in the front of the bus and city law forbade blacks and whites from sitting alongside each other. If a white boarded and did not have a place to sit, the nearest black passengers would have to give up their seats so an entire row would open to the white passenger.
On the afternoon of Dec. 1, Parks and three other black passengers were told to move to the back after whites had filled the front of the bus and a white man needed a seat. While the other three blacks in the row with Parks moved to the back, she did not. Two police officers came to arrest her, and one asked her why she did not move.
"Why do you all push us around?" she replied.
"I was thinking that the only way to let them know I felt I was being mistreated was to do just what I did -- resist the order," Parks recalled years later. "I had not thought about it and I had taken no previous resolution until it happened, and then I simply decided that I would not get up.
"I was tired, but I was usually tired at the end of the day, and I was not feeling well, but then there had been many days when I had not felt well. I had felt for a long time that if I was ever told to get up so a white person could sit, that I would refuse to do so."
Southern historians Dan Carter and David Garrow both said fate figured prominently in the case of Parks and the subsequent leadership role that King played in the 381-day boycott.
"They were figures who ... because of their happenstance presence and happenstance courage, happened to become individual symbols of something that was a very broad grass-roots movement rather than something initiated either by Mrs. Parks or Dr. King," Garrow said.
"I like to believe that she would have been the first to say that she didn't do anything any different really than dozens of other black men and women did," Carter said. "It was just one of those cases where lightning struck, the time was right, the circumstances were right."
Parks was fingerprinted and released on bond. Then she appeared in a segregated City Court and was fined $10 and $4 in court costs. The day of her trial, most blacks stopped using the Montgomery bus system, relying on their feet or on a coordinated community carpool system to do their shopping or get to work. That unprecedented protest lasted 14 months.
While it continued, a federal lawsuit was filed to challenge the city's bus segregation ordinance and the state's segregation laws, and a three-judge panel declared the laws unconstitutional. The U.S. Supreme Court upheld the ruling, and a major wedge was driven in the wall of the segregated South.
"We completely developed the boycott around what she did. And we felt ... the least thing we could do was stay off the buses until we could go back on an integrated basis," said Fred Gray, a lawyer who represented Parks after her arrest and filed the successful challenge to the segregation laws she had violated. "She was very tough, very resolute, very determined. But she did it in her fashion."