On October 4, 1861, at the age of 19, Edmands enlisted with the 24th Regiment Massachusetts Volunteer Infantry as a first sergeant. The regiment reached Annapolis, Maryland in December 1861 and was soon assigned to Brig. Gen. Ambrose Burnside's North Carolina Expedition. Edmands may have taken part in the first two battles of the expedition, the Battle of Roanoke Island and the Battle of New Bern in early 1862. The extent of his involvement is unclear because he was seriously ill for much of the spring of 1862. In the summer of 1862, he was sent home on invalid furlough due to his illness. After his recovery, he began to recruit a new company of volunteers in Boston.