John E. Brownlee was born in 1827 at Ballymena, County Antrim, Ireland, the son of Robert (1805-1885) and Ruth Brownlee. The family was Protestant, of Scots descent. Around 1830 they moved to Killyleagh, County Down, where John Brownlee was raised, and where he was instructed in the trade of his father, a baker. In 1851, at Liverpool, Brownlee married Elizabeth Savage (1827-1883), of Downpatrick, County Down; they would have ten children, at least six of whom survived to adulthood. Shortly thereafter the couple emigrated to America, living initially in New York City, where Brownlee worked as a ship's baker. In 1856, with the help of his half-brother Hugh Young, Brownlee purchased a farm in Sylvania Township, Potter County, Pennsylvania, in the remote north-central part of the state. (The first of Brownlee's relatives to settle in Potter County seems to have been another half-brother, Robert Kennedy Young; the area subsequently attracted a good many family members, Brownlees, Youngs, and Carsons, including John Brownlee's father, Robert, who emigrated from Ireland in 1854). John Brownlee built a saw mill, a grist mill, and a shingle and planing mill, as timber and lumber operations moved into the area after mid-century. He ultimately established a successful lumber manufactory, John Brownlee & Sons, at North Wharton in Potter County. Three of his sons would eventually join the business. Elizabeth Brownlee died in 1883; Brownlee subsequently married Rebecca Courtney, who outlived him.

Of other family members figuring in the papers, mention should be made of the twin brothers Hugh and Thomas Lowry Young, natives of Killyleagh and sons of Robert Brownlee's second wife (and so half-brothers of John Brownlee). Hugh Young (1832-1912) emigrated in 1850 and lived in Potter County before making a name for himself as a correspondent for Horace Greeley's New York Tribune, covering the turmoil in Kansas from a Free Soil perspective. He was a delegate (from Kansas) to the Republicans' first national convention, in 1856. That same year he returned to Pennsylvania, where he would spend the remainder of his life. After the Civil War Young became a financier of some prominence, ultimately serving as National Bank Examiner for the city of Pittsburgh (1891-1903) and president of Pittsburgh's Federal National Bank. Thomas Lowry Young (1832-1888) emigrated in 1847 and joined the U. S. Army in 1848; he remained in the service for ten years, rising to first sergeant. In August 1862 he was commissioned major in the 118th Ohio Volunteer Infantry, a regiment with which he saw considerable service in the field before resigning, as colonel, in 1864. Young then returned to his home in Cincinnati and passed the Ohio bar (1865). By the 1870s, he had a thriving legal practice and had also become a well-respected figure within the state's Republican heirarchy. Chosen as the party's candidate for lieutenant governor in 1875, Young was elected and became Ohio's 33rd governor when the incumbent, Rutherford B. Hayes, left office to become President of the United States. Young thereafter served two terms in the U. S. House of Representatives (1879-1883) before returning to his law practice in Cincinnati.