Owen P. Miles was born around 1832 in Pennsylvania to Nathaniel and Sarah Miles. His father was a farmer who owned $300 of personal property by 1860. The family lived in West Vincent, Pennsylvania, and by 1850, he was working as a teacher. He moved to Mount Carroll, Illinois, in the 1850s. He married Hannah P. Shirk on October 15, 1857, and they had at least eight children: William, born around 1858; Joseph, born around 1860; Jessie, born around 1862; Susie, born around 1863; Charles, born around 1865; Jacob, born around 1868; Judson, born around 1871; and Mary, born around 1873.
He worked as a bookkeeper in Mount Carroll, and by 1860, he owned $2,300 of real estate and $1,500 of personal property. He was elected treasurer of Carroll County in 1859, and he held the position for at least fourteen years. He supported the Union Party during the Civil War. In 1862, he signed an open letter urging Republican congressman Elihu B. Washburne to run for reelection. Then, in May 1865, he joined the National Lincoln Monument Association, which helped build Lincoln’s tomb in Springfield, Illinois.
He supported President Ulysses S. Grant in the election of 1872, and he served as treasurer of a local Grant and Wilson Club. By 1870, he was working as a miller, and he owned $19,000 of real estate and $12,000 of personal property. He employed a domestic servant and a seamstress. He later worked as a cashier at the First National Bank. A local writer described him as a “man of the strictest integrity and methodical business habits.” He died of “heart trouble” in Mount Carroll on September 22, 1896.