He was admitted to the bar in 1861 and commenced the practice of law in Yankton. On September 19, 1861, he was appointed a Brigadier General of Volunteers, serving until July 17, 1862.
When Dakota Territory was formed, Todd was elected as a Democrat to the House, serving from December 9, 1861 to March 3, 1863. He was reelected to serve from June 17, 1864 to March 3, 1865. He was an unsuccessful candidate for reelection in 1864, and returned to Yankton. He served as speaker of the territorial House of Representatives in 1866 and 1867. He was once again unsuccessful in running for Delegate to the Congress in 1868, and died in Yankton County. He is intered in Yankton Cemetery.