Cassius Fairchild (December 16, 1829 – October 24, 1868) was a Wisconsin businessman, politician, and Union Army officer in the American Civil War. He was the brother of Lucius Fairchild, the 10th Governor of Wisconsin, and the son of Jairus C. Fairchild, the 1st State Treasurer of Wisconsin. Early life and career Born in Franklin Mills, Ohio (now Kent, Ohio), Fairchild was educated mostly in Ohio. His father was Jairus C. Fairchild, who was the first State Treasurer of Wisconsin and the first Mayor of Madison, Wisconsin. Cassius was the second of four sons born to Jairus Fairchild and Mrs. Sally Blair Fairchild—his older brother, Charles, died at age four in 1832. The family moved to Cleveland two years later, where Cassius received most of his education and upbringing. At age fourteen, he traveled to the Wisconsin Territory with his uncle, Franklin J. Blair, arriving in the vicinity of Milwaukee. He decided to enter school in Waukesha, and attended the Prairieville Academy (now Carroll University). His parents and siblings followed in 1846, settling in Madison, Wisconsin. Two years later, when Wisconsin became a State, his father, Jairus Fairchild, was elected the first State Treasurer. Jairus Fairchild invested in cranberry farms, lumber interests, and real estate. Within a decade, Cassius would be charged with managing these family businesses. In the 1850s, Cassius Fairchild was elected several times to the Madison City Council, where he served one year as president. In 1859 he became Chairman of the Democratic Party of Wisconsin, and was elected to represent Madison in the 1860 session of the Wisconsin State Assembly. Civil War service Cassius and his brother, Lucius, were volunteers in a Wisconsin militia company known as the Governor's Guard in the late 1850s and gained experience that would become useful in securing leadership positions in the coming war. At the outbreak of the war, Cassius was busy tending to the family's cranberry fields in the remote north. After returning home, he immediately offered his services to the governor for the war effort. In October 1861, Fairchild was appointed major of the 16th Wisconsin Volunteer Infantry Regiment, which was still being organized at the time. He was promoted to lieutenant colonel in December, and the regiment mustered into federal service a month later, on January 31, 1862. Shiloh and aftermath The regiment marched south under Colonel Benjamin Allen on March 16, 1862, and joined Ulysses S.