Peter Mallett was born on May 25, 1824, in Fayetteville, North Carolina. According to an early biographer, his father “was engaged in the manufacture of cotton goods.” He married Annabella Gibbs on November 13, 1848, and they had at least six children: Susan, born around 1850; Charles, born around 1852; Robert, born around 1854; James, born around 1856; Pierre, born around 1861; and George, born around 1863. They moved to New York City in the late 1840s, and he worked as a merchant there. By 1860, he owned $6,000 of real estate and $1,000 of personal property. He employed at least one white domestic servant.
When the Civil War began, he returned to North Carolina and joined the Confederate army. In May 1861, he received a commission as captain of Company C of the 3rd North Carolina Infantry. In May 1862, he was promoted to major and placed in charge of conscription for the state. He eventually earned a promotion to colonel. Union forces captured him near Kinston, North Carolina, on December 14, 1862. He received a parole the following day. He returned to his command in March 1863, and he remained in the army until at least March 1865.
He returned to Brooklyn, New York, after the war, and he worked as a railroad agent. By 1870, he owned $1,500 of personal property. In 1872, he reportedly “went into the warehouse business for the storage of cotton.” His wife died on June 30, 1895, and he died in Wilmington, North Carolina, on November 27, 1907.