John Brownell was born in Saratoga County, New York, on 12 April 1802.  His father, Pierce Brownell, died when John was an infant, and his mother, Margaret (Spike) Brownell, married Alexander Simpson as her second husband.  There were only three children born to Margaret's brief first marriage, but her second marriage produced eleven more.  As a teenager, John was living in the Simpson household in suburban Rochester, New York.
 
Mary Ann French was one of the twelve children born to the three marriages of Peter Price French.  Her mother, Sarah Sterne French, was Peter's third wife, and bore him nine children, including Mary Ann, who was born in the fashionable town of Hampton, New York, in 1806.  Her father was described as "stalwart, over six feet in height, weighing 250 pounds; fresh, florid complexion, dignified in bearing, of military mind and militant habits."  He had purchased a 400 acre farm in Hampton and operated the town's first tavern and store.  In the summer of 1824, Peter Price French moved his family from Hampton to Wells, Pennsylvania, just south of the New York state line, where he built a sawmill.  The community was called French's Mills until 1849.
 
What brought John Brownell to Wells is unknown, but he married Mary Ann French there on 3 November 1831.  Over the next 17 years Mary Ann gave birth to eight children, but, to their great grief, all three of their sons succumbed to disease and died between 1836 and 1838.  They established themselves on a farm in Elkland, Pennsylvania, until 1858, when they "went west" to settle in DeWitt, Iowa.  In addition to running their farm there, John was mechanically minded and invented and patented mechanical implements to assist the farmer.  He spent a great deal of his time "on the road" selling his inventions.  Mary Ann remained back on the farm, managing their home and raising their daughters.
 
Mary Ann Brownell died in DeWitt the day before her 67th birthday, on 8 June 1873.  John remained in DeWitt for another ten years.  In 1883 he moved into the Cedar Rapids home of his daughter, Lucretia Hall.  He died there at the age of 92 on 17 February 1895.  John and Mary Ann are buried in Elmwood Cemetery in DeWitt.