I was shocked and saddened when I heard that an African American teenager, Trayvon Martin, had been killed in Florida by George Zimmerman, a self-proclaimed “neighborhood watchman.”

I was even more shocked when I learned that this incident had occurred almost a month earlier before being covered by “mainstream” media. The story had been covered by the black press when it occurred. Could it be that mainstream media did not initially consider the killing of Trayvon to be important?

Americans, regardless of race, color, ethnicity, religion, sex or age, should be appalled by the killing of Trayvon. In addition to the horror of another teenager being killed is the fact that this incident involved a man said to have a white father and Hispanic mother killing an unarmed black teenager who wasn’t doing anything wrong.

One needs to understand the historical significance of the killing of a black person by a white person in America.

Can you understand how the killing of Trayvon causes fear and anger and makes people recall a system in America that allowed slave owners and other Caucasians to do whatever they wanted to do to black folks without fear of retribution?

Can you understand how the killing of Trayvon generates images of the Ku Klux Klan and other white supremacists threatening, maiming and killing black folks (and others) before and after the Emancipation Proclamation in 1863 and the Civil Rights Acts of the 20th century?

Dr. Martin Luther King, Jr., an advocate for peace, was assassinated on April 4, 1968, after which, rioting occurred.

Folks have voiced a fear that a race riot may occur if Zimmerman is not charged with a crime. This fear may be valid. I felt like rioting myself when I learned that Mr. Zimmerman was not charged with anything. Thank goodness religious and community leaders have put forth efforts to defuse rioting.

America has long been described as a Christian nation. But Christian by whose standards? Can the mistreatment of Native Americans, enslavement of blacks, interment of the Japanese, continued discrimination against Blacks, Asians, Jews, Polish, Irish, Gays, old folks, women, children et al. be categorized as Christian behavior? Not according to what I remember about the description of Jesus, the person on whom Christianity is supposed to be based.

It’s 2012, and although America has come a long way in addressing genocide, discrimination and the harassment of certain groups, it still has a mighty long way to go.

Peggy Tarr has been a columnist for the Evanston RoundTable since its founding in 1998. Born in Bruce Springsteen's hometown of Freehold, New Jersey, she graduated from Rutgers University with a degree...