He attended Caledonia County Grammar School and graduated from Dartmouth College in Hanover, New Hampshire in 1851. Willard studied law and was admitted to the bar in 1853.
He served as a United States. Representative from Vermont. He began the practice of law in Montpelier. In 1855 and 1856 he was Secretary of State of Vermont.
He became editor and publisher of the Daily Green Mountain Freeman in 1861, and served in those positions until 1873.
Willard was elected as a Republican candidate to the Forty-first, Forty-second, and Forty-third Congresses, serving from March 4, 1869 until March 3, 1875. He served as chairman of the Committee on Revolutionary Pensions during the Forty-first and Forty-second Congresses.
He was an unsuccessful candidate for reelection in 1874 to the Forty-third Congress. Willard died on June 8, 1880 in Montpelier, and is interred in Green Mount Cemetery in Montpelier.
He declined reelection, then served as member of the Vermont State Senate in 1860 and 1861. After leaving Congress, he resumed the practice of law in Montpelier and served as a member of the commission to revise the laws of Vermont in 1879 and 1880.