Warren W. Kerr was born on January 29, 1842, in Putney, Vermont, to Valentine Kerr and Rhode Winslow. His father was a farmer who owned $100 of real estate in 1850. Kerr grew up and attended school in Putney. He enlisted in the Union army on December 10, 1863, and mustered in as a private in Company I of the 8th Vermont Infantry on January 4. He was wounded at Cedar Creek on October 19, 1864, and he mustered out on May 25, 1865.
He returned to Putney after the war, and he married Adaline Whitney on October 8, 1867. They had at least four children: Walter, born around 1869; Eugene, born around 1875; Effie, born around 1876; and Mabel, born around 1879. He applied for a federal pension in July 1865 and eventually secured one. He worked as a farmer, and by 1870, he owned $1,500 of real estate and $1,000 of personal property. He died by suicide in Putney on August 7, 1881.