 From 1850 until 1853 he also served in the Missouri Senate before returning to private practice as a partner in a law firm back in St Louis.He formed the Committee of Safety to oppose the growing southern factions in the lead up to the American Civil War and was a member of the Missouri Constitutional Convention that declared Missouri's loyalty to the Union in 1861.Broadhead was commissioned as a lieutenant-colonel in the 3rd Missouri cavalry and assigned to General Schofield, and was also served as an advisor for the preliminary constitution which dictated the government of Missouri during the Civil War.