Who would have thought that a 42-year-old black seamstress sitting on a bus in Montgomery, Ala., would become one of the true icons of the American civil rights movement?

Rosa Parks was just sitting there, riding home from her job at a department store on Dec. 1, 1955. But when she was ordered to give up her seat to a white person who had boarded the bus, she didn’t stand up. She had had enough of the indignities of the segregated South. It was time, in her judgment, to take a stand by sitting down.

Parks, who died in Detroit Monday night, was just an average person, but she had a background that was somewhat unusual for black people at the time. She had graduated from high school in 1933, putting her among only 7 percent of the black population at that time. And she was no stranger to the budding civil rights movement. She was a volunteer secretary to the president of the Montgomery chapter of the NAACP and had attended a workshop on racial discrimination in the summer of 1955.

She knew, as she sat on that bus, waiting for police to arrive, that she probably would find support among her friends in the civil rights struggle. But, as she sat there, she was alone, one woman doing what she thought was the right thing regardless of the consequences.

Those consequences were significant. After she was arrested and fingerprinted, she landed in jail and was bailed out by her boss at the NAACP. She lost her paying job at the department store and her husband quit his job after his boss ordered that there be no mention of Rosa or her case. In August 1957, the couple was driven out of Montgomery by telephone death threats and other threats of violence.

In the meantime, however, Rosa Parks had become a hero among fellow blacks. Her simple action inspired other blacks to boycott Montgomery buses in protest of her treatment. She was found guilty of violating the segregation law, but, less than a year later, her case landed in the U.S. Supreme Court, which struck down Alabama’s segregation law.

Rosa Parks provided a focal point for the civil rights movement to come. Her treatment for the simple offense of sitting on a bus shined a harsh light on the daily indignities of segregation. Her story was somewhat overshadowed during the turbulent 1960s, but, in her later years, Parks received the recognition she deserved for her simple, determined act of disobedience. Her story now is part of civil rights history.

Was she a great woman? Maybe. Or maybe she was just like the rest of us, an average person who had a chance to do the right thing even though it would have been easier to just go along. There’s a lesson in that for all of us.

If you ever are tempted to think that one person can’t make a difference, just remember Rosa Parks.