(CNN) -- In the wake of Barack Obama's second inauguration, it is easy to forget about the daily indignities and terror African-Americans have endured; easy to forget that simply surviving segregation required ordinary people to engage in extraordinary acts of courage every single day.
Like so many African-Americans who came of age during the era of Jim Crow laws, Rosa Parks' courage was not limited to one day or one act. Parks cultivated courage throughout her life. She called on it during the darkest days of the Depression when African-Americans were targeted for lynching and rape; deployed it throughout the civil rights era when white vigilantes burned crosses and bombed churches to thwart struggles for justice; and armed herself with it to battle inequality and lack of opportunity on the dusty backroads of Alabama and the broad boulevards of Detroit.
Monday, on the 100th anniversary of Rosa Parks' birth, let us remember how brave she was to continuously defy the segregated system that denied her humanity.
In 1943, Rosa Parks joined the local NAACP. In addition to serving as secretary, she also had the job of investigating and documenting acts of racial violence, something that required vast stores of bravery and nerve.
Her investigative work for the NAACP exposed her to the horrific racial and sexual violence whites visited upon blacks who refused to abide by the segregated status quo.
"Things happened," Parks said, "that most people never heard about."
In 1944, she helped organize a nationwide campaign to defend Recy Taylor, an African-American woman kidnapped and gang-raped by a group of white men in Abbeville, Alabama.
A few years later, she fought to free Jeremiah Reeves, a black teenager later executed for rape after having a consensual relationship with a white woman.
In 1949 she worked with local activists to defend Gertrude Perkins, a black woman kidnapped and raped by two white Montgomery, Alabama, police officers.
In the early 1950s, she turned her attention to the segregated city buses, where black women were often beaten, harassed or assaulted.
When Parks refused to give up her bus seat to a white man on December 1, 1955, she clearly knew the dangers she faced by choosing arrest. She knew that some black women in the custody of Southern white policemen disappeared forever. Others were beaten, sexually harassed, and raped. There was no way to be without fear as the police officers drove her to jail.
When Parks called home, her mother immediately asked, "Did they beat you?" That these were her first words speaks volumes about the context and the courage of Parks' protest.
A few days later, Parks lost her job. Then the harassment and death threats began. After a massive meeting of the White Citizens' Council on February 10, 1956, where segregationists promised to teach Rosa Parks a "harsh lesson," she asked the boycott leaders to provide night watchmen at her home.
When vigilantes started bombing black homes, churches and businesses in Montgomery, Parks decided she would rather live somewhere else than die in Alabama. So she moved to Detroit in 1957.
She quickly realized the Motor City was no promised land. Instead of retiring from the nascent civil rights movement, however, she devoted herself to the freedom struggle for the next five decades.
As we celebrate the 100th anniversary of Rosa Parks' birth, let us honor her not for a single act of courage, but for her determined and spirited commitment to confront and resist injustice wherever and whenever she found it. That she devoted herself, often at considerable risk, to exposing and destroying racial violence and inequality for nearly 70 years makes her all the more astonishing.
- -The opinions expressed in this commentary are solely those of CNN's Danielle McGuire.