(The Root) — Who defined black America over the last year? Who is redefining their field, from the arts to the academy? Who are the most influential African Americans 45 and under? As we have since 2009, The Rootlooked back at the most significant moments in black news and culture and asked, “Who made this happen?” For more than 800 nominees, we measured their reach in the world and rated the substance of their contributions. The result: The Root 100 annual ranking of the most influential African-American leaders in 2013.

Our 100 honorees pushed the limits of their chosen fields, both in the spotlight and behind the scenes. From breathtaking performers to scrappy activists, these leaders and achievers shaped the black experience in America this year, and we’re certain they’ll shape the future.

Our top-ranked honoree for 2013 will come as no surprise to anyone tuned in to the year’s most urgent civil rights causes. NAACP President and CEO Benjamin Todd Jealous, the youngest person ever to lead the organization, is credited with bringing an energetic and progressive focus to issues like stop and frisk, voter suppression, marriage equality and criminal justice. Our formula ranked this influencer in the top spot before he announced his decision to step down from his post effective Dec. 31. So, the forthcoming end of “the Jealous era” makes the recognition of his game-changing leadership all the more poignant.

Ranked No. 2 is Newark, N.J., Mayor Cory Booker, who is poised to make history if he wins his state’s Senate seat. Serena Williams, whose unparalleled athleticism further solidified her place in American sports history this year, ranked third.

Next in the rankings is last year’s top honoree, MSNBC host and Tulane University professor Melissa Harris-Perry. Harris-Perry has continued to use her program to lead discussions that go far beyond typical cable TV talking points on pressing political and cultural issues. She’s also leveraged the #Nerdland platform to give an audience to black and brown scholars and activists whose much-needed insights don’t get nearly enough airtime elsewhere. Also in the top five, Shawn “Jay Z” Carter. Aside from his artistry, he’s cultivated a career that’s pushed the definition of what it means to be a mogul, and a perspective that’s forced us to debate the very meaning of black wealth and influence.

Some deemed George Zimmerman’s murder trial the “trial of the century.” By any account, it was an unforgettable 2013 storyline. And with it came unforgettable leaders who helped the country make sense of what many saw as a grave injustice. Among them: Martin family attorney Benjamin Crump (No. 11), who continued to help define the national narrative about racial profiling. New to the list this year is Phillip Agnew(No. 45), the brave young activist at the head of the Dream Defenders’ push for legislative change in the wake of the tragedy.

The Zimmerman trial provided rich fodder for deep reporting and commentary on race, justice and rights that will help define the country’s memory of the case. On our television screens and tablets, making sense of legal minutiae and the larger meaning of every development were astute writers and analysts including honorees William Jelani Cobb (No. 12), Adam Serwer (No. 34), Joy-Ann Reid (No. 17), Charles Blow (No. 27),Ta-Nehisi Coates (No. 19), Sunny Hostin (No. 68) and Jamelle Bouie (No. 58).

When it came to the closely related issues of racial profiling and deadly stereotypes about African-American men, Ryan Coogler (No. 6), used film as his medium, with the heartbreaking hit Fruitvale Station.

And for their part in creating film and television presenting complex images of African Americans against the much-needed lighter storylines, we honor Shonda Rhimes (No. 9), Kerry Washington (No. 7), Mara Brock Akil(No. 66), Issa Rae (No. 31) and Ava DuVernay (No. 40). Onstage, Adepero Oduye (No. 97) is one to watch.

We calculated traditional and social media reach for every nominee and, unsurprisingly, numerous celebrities rank highly for The Root 100 on this criterion. To make the cut, however, nominees needed to score well for reach and substance. The culture-shaping stars making the cut this year included Kendrick Lamar (No. 24),Jamie Foxx (No. 16), Beyoncé (No. 18) and Janelle Monáe (No. 32).

The substance scores also help those who may have lower public profiles but whose innovations and leadership influence our lives in other vital ways. Tristan Walker (No. 33), who founded CODE2040 to place highly motivated young students of color into tech internships, is now entrepreneur-in-residence at Andreessen Horowitz. Monique L. Nelson (No. 83) heads up the longest-standing multicultural advertising agency in the United States. Kimberly Bryant (No. 44) has created a global movement that focuses on teaching code to girls of color. Their dogged work and creativity earned them places on this year’s list.

We’ve also highlighted elected officials including Nina Turner (No. 47), Aja Brown (No. 95), Stephanie Rawlings-Blake (No. 48), Anthony Foxx (No. 15) and Hakeem Jeffries (No. 72), whose bold leadership on issues impacting African Americans has resonance beyond their individual jurisdictions. Meanwhile, honorees like David Johns (No. 60), executive director of the White House Initiative on Educational Excellence for African-American, and Jonathan McBride (No. 71), assistant to the president and director of Presidential Personnel, exert their influence behind the scenes.

Many others made the list in fields as diverse as literature (Kiese Laymon, No. 81; Jesmyn Ward, No. 79), transgender activism (Kortney Ryan Ziegler, No. 29), athletics (LeBron James, No. 21; Jason Kidd, No. 22), law (Randall Jackson, No. 84) and academia (Khalil Gibran Muhammad, No. 54; Brittney Cooper, No. 73;Christine P. Fleming Hendon, No. 100).

Please join us in congratulating this year’s winners. We’d love to hear what you think.