His pedigree traces to major sires of significance, including his grandsire Storm Cat and his damsire Unbridled.

He was named after Shackleford Banks, a barrier island system in North Carolina, home to a herd of feral Banker horses and a place often visited by his owners.

[3] Lauffer and Cubbedge put Shackleford up for sale as a yearling at the Keeneland auction, but when the bids failed to reach the reserve price of $275,000, they bought back the colt and kept him.

That race was won by eventual Blue Grass Stakes runner-up and Kentucky Derby starter Twinspired.

In that race, he broke well and stalked the leader from second position, then put on a burst of speed and drew clear to win.

[7][8] Romans next entered Shackleford in the Grade II Fountain of Youth Stakes on February 26 at Gulfstream Park.

On that turn, he took over the lead from Arch Traveler and To Honor and Serve in a field that stretched 14 lengths back to Dialed In at the rear.

Three strides from the wire, he was caught by eventual Kentucky Derby co-favorite Dialed In and just missed the win, finishing second by a head.

[12] In the 2011 Kentucky Derby, Shackleford broke well and outran Comma To the Top for the lead passing the stands for the first time.

Castanon then used the whip and Shackleford accelerated, holding off the strong late charge of Animal Kingdom to win by half a length.

[17] Shackleford's first- and fourth-place finishes in Preakness Stakes and Kentucky Derby respectively handed the Triple Crown's consolation title to Animal Kingdom.

That finish put Shackleford squarely in contention (along with Animal Kingdom) for the "Eclipse Award" as the American Champion Three-Year-Old Male Horse.

On July 31, 2011, Shackleford lost by a head in the Haskell Invitational at Monmouth Park in New Jersey to the Bob Baffert-trained colt Coil, who had a six-pound weight break advantage.

[24] On February 11, Shackleford was seventh out of a field of eleven horses in the Grade 1 Donn Handicap run at Gulfstream Park.

Longshot Jackson Bend won by a nose over Caleb's Posse, with Shackleford another length and a half back in third.

[27] On Memorial Day, May 28, 2012, Shackleford raced in what analysts called the deepest field of the year featuring favorites To Honor and Serve, Caleb's Posse, Jackson Bend and Caixa Eletronica in the $750,000 Grade 1 Metropolitan Handicap (known by most as the Met Mile run at one mile on the dirt at Belmont Park).

Shackleford had just enough left to withstand the furious late rush of Caleb's Posse, stopping the clock in 1:33 1/5 over the fast track to win by a nose.

With this win, Shackleford turned the tables on old rival Caleb's Posse, who beat him in the 2011 Breeders' Cup Dirt Mile.

[32] Shackleford sired his first winner on May 27, 2016 when juvenile colt Little Nappy won a 4+1⁄2 furlongs (3,000 ft; 910 m) maiden special weight at Gulfstream Park.

[2][37] In addition, Forestry's maternal grandsire was Pleasant Colony,[1] who won both the Kentucky Derby and, like Shackleford, the Preakness Stakes.

Unbridled has sired progeny who separately won each of the Triple Crown races, including Grindstone, Red Bullet, and Empire Maker,[2] achieving the feat only three years after his grandsire Mr. Prospector did with Fusaichi Pegasus, Tank's Prospect and Conquistador Cielo.