From Florida to New York City, the Motor City and the Lone Star state, thousands of people in cities across the U.S. participated in Justice for Trayvon rallies.

A week after a verdict of not guilty was delivered in the George Zimmerman trial, thousands of supporters of Trayvon Martin and his family gathered across the country to press for further federal investigation into the circumstances surrounding the teen's shooting death.

“I’d like the world to know that Trayvon was my son. He was a loved child. He did nothing wrong and we’re not going to let them persecute him the way that they have,” Tracy Martin, father of Trayvon Martin, said on Saturday, at a vigil held in Miami, Fla.

“I vowed to Trayvon, when he was lying in his casket, that I would use every ounce of energy in my body to seek justice for him. I will fight for Trayvon until the day I die. Not only will I fight for Trayvon, I will fight for your child as well,” Martin said.

A Florida jury found Zimmerman not guilty of 2nd degree murder and manslaughter on July 13. Zimmerman says he shot the teen in self defense.

The Miami vigil is one of over 100 “Justice for Trayvon” vigils, planned by Rev. Al Sharpton’s National Action Network, taking place outside of courthouses across the country on Saturday.

Martin’s mother, Sybrina Fulton, attended a vigil in New York City with Sharpton, who also hosts a show on MSNBC. Among the demonstrators who joined them were entertainers Jay-Z and Beyonce.

Pastors and speakers at the Miami vigil asked for prayer and action from the African-American community, and called for demonstrations against 'Stand Your Ground' laws. While Zimmerman's defense team did not ask for a hearing under the self-defense law in his case, instructions to the jury borrowed language from the statute.

Angel Valentin / Getty Images file Demonstrators James Alvarez, 34, and Yesenia Mena, 29, hold signs in front of the Freedom Tower in downtown Miami a day after the verdict to the George Zimmerman murder trail on July 14, 2013 in Miami, Florida.

“Last Saturday was a wake-up call,” said Bishop Victor T. Curry, a Miami minister who said that African-Americans continue to face inequalities.

“Last Saturday said to the rest of us that we have people that will go in and come out with a verdict that says we will give you a license to pursue an African-American teenager. We are giving you a license to stand behind a law that is ungodly and unjust. 'Stand Your Ground' was wrong then and it’s wrong now,” Curry said before calling for a march on Washington, D.C., in August.

In New York City, Sharpton led a call and response with the crowd, chanting: “What do we want? Justice! When do we want it? Now!” and “I am Trayvon Martin.”

Sharpton asked supporters to do three things: protest ‘Stand Your Ground’ laws, participate in a march on Washington, D.C., and pressure the Department of Justice to look further into the case.

“Across generations, across incomes, we are not going to be silent. We are going to stand up for what’s right. We are going to stand up for justice. When you mess with one of the children, the family needs to come together,” Sharpton said.

Trayvon Martin’s mother, Sybrina Fulton, also spoke to the crowd.

“Trayvon is not here to speak to himself. It’s very important as parents, godparents, aunts, uncles, and cousins that you speak up for your children,” she said.

“Trayvon was a child, and I think sometimes it gets lost in the shuffle. As I sat in the court room, it made me feel like they were talking about another man. It wasn’t. He was a child.”

Her words seemed to strike a chord with parents who attended the vigil.

"I've got four beautiful daughters. I want them to look forward rather than behind their backs," New York City resident Maria Lopez, 31, who attended the event with her children, told Reuters.

The many vigils come one day after President Barack Obama said at a daily press briefing that Trayvon "could have been me 35 years ago." In his seemingly impromptu remarks, Obama asked if there is "more that we can do to give them [young African-American men] the sense that their country cares about them and values them and is willing to invest in them?”

“Senseless violence is a disease and we as a people have the cure, we just need to come together,” Tracy Martin said at the Saturday vigil.

Editor's note: George Zimmerman has sued NBC Universal for defamation. The company strongly denies the allegation.

NBC News

Related: