Sybrina Fulton, mother of Trayvon Martin, holds up a card with a photo of her son as she speaks at the National Urban League's annual conference, Friday, July 26, 2013, in Philadelphia.
Wednesday marks two years since the shooting death of 17-year-old Trayvon Martin in Sanford, Florida.
His death drew national attention, bringing up race and Florida's controversial "stand your ground" law.
George Zimmerman, the neighborhood watch volunteer who said he shot the teen in self defense, wasn't charged right away. He was eventually charged with second degree murder and was acquitted last year.
Vigils were held across the country on Wednesday to remember Martin. Also on Wednesday, the parents of another slain teenager said they would join Trayvon Martin's parents in a March rally to focus on the stand your ground law.
Ron Davis and Lucia McBath said Wednesday they will visit Tallahassee on March 10 for a rally to protest the law.
Their son, Jordan Davis, was shot by Michael Dunn, who was convicted earlier this month on multiple counts of attempted murder for shooting into a carful of teenagers outside a Jacksonville convenience store in 2012.
However, the jury couldn't reach a verdict on the first-degree murder charge against Dunn in the death of teenager Jordan Davis. A mistrial was declared on that count.
The Associated Press contributed to this report.