On Tuesday, Congress will bestow its highest civilian honor — posthumously — to the young victims of a deadly Alabama church bombing from the Civil Rights era.

The Congressional Gold Medals for Addie Mae Collins, Denise McNair, Carole Robertson and Cynthia Wesley come 50 years after the Black girls were killed by a Ku Klux Klan bomb. Just as the federal recognition is long in coming, so was justice.

The plot to bomb 16th Street Baptist Church can be traced to a once-remote spot along Alabama's scenic Cahaba River. Suburban traffic now rumbles above a deserted, gravelly spot under the Cahaba River Bridge.

"But in the day it was apparently a hot spot for some of the more violent members of the Klan to sit down here and talk and do their dirty work," says former U.S. attorney Doug Jones. Four girls were killed in the bombing of the 16th street Baptist Church, in Birmingham, Ala., on Sept. 15, 1963. One man was convicted in the crime 1977, but more than two decades would pass before any other suspects were tried for the murders. 

Jones was the federal prosecutor who tried and convicted klansmen Thomas Blanton and Bobby Frank Cherry in 2001 and 2002, for the murder of the four Black girls killed in one of the most notorious racially-motivated crimes in U.S. history. Blanton and Cherry were part of a small group of disgruntled White supremacists who didn't think the Klan was doing enough to stop the rising tide of the Civil Rights Movement in 1963.