University of Wisconsin–Madison.
He came to Wisconsin in 1852 and settled at Windsor, Wisconsin. In 1857 he enrolled in classes at the University of Wisconsin. During the American Civil War he assisted in raising a company for the 36th Wisconsin Volunteer Infantry Regiment, and was mustered in as captain in March, 1864.
They joined the Army of the Potomac in May.
Within one hundred days the regiment was nearly annihilated in battles around Richmond and St. Petersburg, during which time Warner received commissions to major, lieutenant-colonel and full colonel. He lost an arm on August 14, 1864, while in command of the regiment at the Second Battle of Deep Bottom.
He returned to his regiment in November and commanded it until the close of the war. His regiment participated in the Richmond-St. Petersburg Campaign in 1864 and 1865.
Was in the final charge April 2 at St. Petersburg and present at the surrender of Robert East. Lee at Appomattox Court House April 9, 1865.
And mustered out July 12, 1865. Warner was elected to the Senate as a Unionist in 1867 (succeeding fellow Unionist Willard Chandler) and as a Republican in 1868. He was succeeded by Republican Nelson Williams.
In 1873, he ran for the Assembly"s 2nd Dane County district, which at that time consisted of the Towns of Blooming Grove, Burke, Dunn and Windsor, and the City of Madison) to succeed fellow Republican Levi Baker Vilas, who was not a candidate for re-election.
He lost with 995 votes, to 1,388 for merchant Philo Dunning, the candidate of the Reform Party (a short-lived coalition of Democrats, reform and Liberal Republicans, and Grangers. In 1877 he became Superintendent of the Poor for Dane County.
In 1883 he was elected to the revised second Dane County Assembly district (Bristol, Burke, Cottage Grove, Deerfield, Medina, Sun Prairie, Vienna, Windsor and York) to succeed fellow Republican Elisha Keyes for 1883, receiving 980 votes against 945 for Democrat A. L. Durfey and 1 for Prohibitionist J. F. Taylor. He was not a candidate for re-election in 1884, and was succeeded by Republican Charles Buell.
He served two years (1867-1868) as a Unionist member of the Wisconsin State Senate and one (1883) as a Republican member of the Wisconsin State Assembly from Dane County.