The Youngest Person Executed in the United States

From Wikipedia:

The execution of George Stinney was carried out at the South Carolina State Penitentiary in Columbia, South Carolina, on June 16, 1944. At 7:30 p.m., Stinney walked to the execution chamber with a Bible under his arm. Standing 5’1″ and weighing just over 90 pounds, he was small for his age, which presented difficulties in securing him to the frame holding the electrodes. Neither did the state’s adult-sized face-mask fit Stinney; his convulsing exposed his face to witnesses as the mask slipped free. Stinney was declared dead within four minutes of the initial electrocution From the time of the murders until Stinney’s execution, eighty one days had passed.