Rand volunteered for military service when a telegram was read in Batavia announcing Lincoln's call for 75,000 volunteers. He was the first to join the Union war efforts from Batavia, and was one of the first in the country to do so. His unit, Company K of the 12th New York Volunteers, traveled to Virginia and fought at Blackburn's Ford during the First Battle of Bull Run in July of 1861. When part of his regiment fled the battle, Rand remained, continued to fight using an old musket, and joined another unit. During the Battle of Gaine's Mill in June of 1862, Rand was shot in the shoulder, captured, and imprisoned at Savage's Station, Virginia. He was exchanged soon thereafter, and mustered out to the Veteran Reserve Corps on August 30, 1862 as a 1st Lieutenant. At the end of the war he assisted with Reconstruction in Texas as sub-assistant commissioner of the Bureau of Refugees, Freedmen, and Abandoned Lands.