Alexander grew up in the Hyde Park neighborhood of north St. Louis, Missouri in an area described as rough, gang- and drug-infested.

[1] Alexander was mentored by various people at a young age including Former NFL players Eric Drain and Demetrius Johnson, principal of Clay Community Education Center Frank Muelhauser, and PE teacher, Brad Slinkard.

Alexander made it to the final round of the 2004 Olympic trials, where he battled Rock Allen to a draw and was knocked down once before losing on a tie-breaker.

[4] At age 17, Alexander made his professional debut, defeating Vincent Torres by first round technical knockout in Sault Sainte Marie, Michigan.

[4] He went up against former WBO junior welterweight champion DeMarcus Corley on January 19, 2008, at Madison Square Garden in New York City.

Alexander was next scheduled to face two-time champion Juan Urango of Colombia in a title unification bout.

The 6 March 2010 bout was held at the Mohegan Sun in Uncasville, Connecticut and was televised on HBO's "Boxing After Dark" telecast.

Alexander's next fight, on January 29, 2011, took place against Timothy Bradley, which he lost via 10th round TD after an unintentional head-butt forced a stop to the bout.

On February 25, 2012 Alexander moved up to welterweight and put on a dominating performance against highly regarded and hard-charging Marcos Maidana.

Alexander lost the WBC Silver Welterweight title to Amir Khan on December 13, 2014 by a lopsided unanimous decision with scores of 119-109, 118-110, 120-108.