ABC News' MaryAlice Parks reports:
The four girls killed 50 years ago in the bombing of the 16th Street Baptist Church in Birmingham, Ala., received the Congressional Gold Medal - the highest civilian award given in U.S. - on Tuesday before a packed hall at the Capitol.
Sen. Richard Shelby, R-Ala., described the day of the bombing, which killed Addie Mae Collins, Denise McNair, Carole Robertson and Cynthia Wesley, as the "darkest day in the history of Birmingham."
Had they survived, the girls would now be in their 60s, "and they probably would have voted for Barack Obama," said Sen. Barbara Mikulski, D-Md.
Under the watchful eye of a statue of civil rights icon Rosa Parks, Senate and House leaders from both parties stated that in their deaths, the girls had become icons of social justice.
"They will join Rosa Parks as the heroes of the civil rights movement," said Rep. Spencer Bachus, R-Ala.
Rep. Terri Sewell, D-Ala., co-authored the initial legislation to award the Gold Medal with Bachus, while Shelby and Sen. Jeff Sessions joined efforts in the Senate. The measure passed both chambers of Congress unanimously in May.
Today, Sewell credited the girls' sacrifice in paving the way for her own career as the first African-American congresswoman from the state.
"Others sow the seeds for the harvest that we all now reap," Sewell said. "I not only question where I would be without the influence of these four little girls, but more importantly, I question where America would be."
Senate Majority Leader Harry Reid spoke of the symbolism of the only remaining stained glass window in the church after the bombing five decades ago. The window showed Jesus leading a group of children to safety. Reid quoted Dr. Martin Luther King Jr. who said the girls' sacrifice, "Set us on a path towards making justice a reality for all of God's children."
House Majority Leader Eric Cantor spoke of the resolve of the Birmingham community.
"The bombs that September morning may have shaken the walls of the church," Cantor, R-Va., said, "but they could never shake the will of the people who often gathered under its steeple seeking the divine right of equality."
Looking to the future, House Minority Leader Nancy Pelosi said there is still work to be done in the civil rights movement today, commenting that Rosa Parks was also watching when the Supreme Court overturned portions of the Voting Rights Act in June.
"She was looking over our shoulder then to see what we would do," said Pelosi, D-Calif. "And we won't disappoint you, Rosa Parks."
An emotional House Speaker John Boehner choked back tears as he concluded the ceremony.
"Once again, our children have led us to this simplest of notions. They bring us together. They give us hope when ours runs out," said Boehner, R-Ohio. "May we serve their memories with love and honor."