During the Civil War, 100 Watertown pioneers served in the Union Army in infantry, artillery, and cavalry regiments. By 1865, no men between the ages of 18 and 45 remained in the area, and the town stood still. A dozen Watertown soldiers died in the war, and many others were wounded or suffered from disease. After the war, returning soldiers helped develop the Watertown community through business and farming. Watertown was also known for its livestock fairs, major events that drew settlers from miles around, crowded the boardwalks, filled every hitching post with teams of horses, and turned the center of the road into a corral where 200 to 300 cattle were bartered to city buyers, while horse trading dominated the day amid the sounds of horses, cattle, and pigs. Watertown's first industry was milling: in the fall of 1856, Alexander Moore, encouraged by Isaac Lewis, brought in a portable sawmill and began sawing lumber so several houses and a hotel could be built before winter; in 1859, Eli F. Lewis and Isaac I. Lewis took possession of the mill, moved it to the east side of the river, and also built and operated a grist mill. Milling remained important in the mill reserve area south of downtown, though between 1856 and 1884 the mill was destroyed by fire three times; in 1884 it was rebuilt at the south end of Lewis Street, burned again in 1920, and was replaced there in 1921 by the Watertown Co-Op Grain and Fuel Association. The Crow River is prone to flooding, and in May 1965 it reached a record high of about 18 feet in Watertown, affecting many homes and businesses, prompting construction of an emergency levee downtown, and forcing evacuations along the river. Through hardship, Watertown's early men, women, and children worked so their families and later generations could live, learn, work, and play there.