Forty-five years ago, one of the most pivotal racist attacks of the civil rights era occurred. Local members of the Ku Klux Klan planted a bomb under the steps of the 16th Street Baptist Church in Birmingham, Ala., on a Sunday morning, Sept. 15, 1963. The explosion killed four young girls, three of them age 14 and one of them only 11 years old.

Most popular accounts of the civil rights movement mark 1963 as the apex of nonviolence. In August of that year, the Rev. Martin Luther King Jr. gave his famous “I Have a Dream” speech on the steps of the Lincoln Memorial facing an audience of 250,000 supporters.

But while King praised nonviolence, racist groups and individuals engaged in violence throughout the region. Birmingham was at the center of the fray. There were so many buildings and homes blown up by vigilantes there that the town was dubbed “Bombingham.”

Convictions for these crimes were rare. It was not until 1977 that prosecutors in Alabama aggressively went after the culprits in the 16th Street Church bombing, resulting in the conviction of KKK member Robert Chambliss that same year.

Things have changed in America since 1963. No one would argue with this. My own grandmother, who was born in Mississippi in 1901 and worked as a sharecropper and maid, never believed the day would come that a black man would be nominated for president by a major political party.

But let’s not celebrate the postracial Promised Land too soon. There is not only persistent racism in the United States, there is also persistent racist violence and the hatred that fuels it.

Sen. Barack Obama has had numerous death threats. The threats were so prevalent and so serious that he received Secret Service protection well before he was the Democratic Party nominee. In Denver around the time of the Democratic National Convention, the Secret Service had to investigate another plot against his life, and arrested four people who allegedly planned on shooting him with a rifle from long range.

In America, people of color are still victims of racially motivated violence.

In May a federal jury in Kansas City convicted two men of the racially motivated murder of a black man, William McCay, three years before.

Last month, Luis Ramirez, a Mexican immigrant and father of two, was beaten to death by four white teenagers in Shenandoah, Pa. They hurled racist epithets along with kicks and punches.

It is important to remember the lessons and legacy of Birmingham in 1963.

It is equally important to not turn a blind eye to the ongoing instances of racial harassment and violence today, from the threats of lynching that sparked the Jena 6 case last year to the numerous hate crimes that get reported to the Justice Department and civil rights watchdog groups each year.

It is not only naive to think we have completely eradicated racism in America, it is dangerous.

To be sure, racist violence never consumed the entire population or even the majority. Most people of color were not direct victims. And most whites did not throw the blows or the bombs. They simply looked the other way.

Apathy or willful ignorance in the face of racism and injustice yields the same net result, whether it is the blatant and widespread racism that showed itself in Birmingham, or the more subtle but no less real racism of today.

We couldn’t afford that apathy or that ignorance yesterday. We can’t afford it now.

Barbara Ransby is an associate professor in the department of African American Studies and History at the University of Illinois at Chicago. She is the author of the award-winning biography, “Ella Baker and the Black Freedom Movement: A Radical Democratic Vision.” She can be reached at pmproj@progressive.org.