Byron Seth Cobb was born around 1842 in Vermont to Stillman Cobb and Betsey Ann Haven. His father was a farmer who owned $600 of real estate and $210 of personal property by 1860. Cobb grew up and attended school in Weston before beginning work as a farmer. His father died around 1867. By 1870, he was living in Weatherfield, Vermont, and he owned $1,000 of real estate and $500 of personal property. He married Elizabeth Shattuck around 1874. He died of typhoid pneumonia in Weston on April 14, 1878.