From Ohio History Central
Camp Dennison was a Union Army training camp during the American Civil War. It was located in the town of Germany, Ohio, seventeen miles north of Cincinnati. George McClellan, a general in the Ohio militia, chose Germany as the site for a camp. The camp was named for Ohio Governor William Dennison. Camp Dennison was strategically located near Cincinnati, the Ohio and Little Miami Rivers, and the Little Miami Railroad. The rivers and railroad provided quick transportation from various parts of Ohio and surrounding states. The presence of troops at Camp Dennison also provided Cincinnati with soldiers to protect this important manufacturing city from Confederate attack. Camp Dennison encompassed more than five hundred acres of land.
The task of laying out the camp fell to Colonel William Rosecrans. Construction of barracks began in 1861. The barracks provided homes for the more than fifty thousand men who passed through the camp during the Civil War. They were located to the south of the Little Miami Railroad. In 1862, military officials established a hospital on the northern edge of the camp, just to the north of the railroad. It eventually held more than 2,300 sick or injured soldiers.
Upon the Civil War's conclusion, Camp Dennison was closed. Local residents dismantled the barracks and hospital, scavenging building supplies to construct their own homes. Hoping to increase the community's population, Germany residents changed the town's name to Grand Valley, but the railroad continued to use Camp Dennison as the name of the local station.