James Simpson was born around 1824 in Washington County, Pennsylvania, to Robert and Anne Simpson. His father was a farmer who owned $12,400 of real estate and $2,953 of personal property by 1860. The family lived in Cross Creek, Pennsylvania, and by 1850, he was also working as a farmer. He married Catherine Johnson around 1862, and they had eight children: Annie, born around 1863; Robert, born around 1865; Frank, born around 1867; Rosa, born around 1869; Rowland, born around 1872; James, born around 1874; Homer, born around 1876; and Brainard, born around 1877. According to a local writer, he “made a study of history and particularly that of Western Pennsylvania…He was acknowledged to be the best historian of this section of country.” He remained in Cross Creek for the rest of his life, and he died there of paralysis on December 18, 1902.