In June 1861, Confederate supporters in Memphis erected earthworks to protect the city here at Fort Pickering, the site of a frontier-era fortified trading post. Capt. William Pickett and his company of sappers and miners supervised the slave and free black laborers who built the stronghold. Local volunteers mounted artillery and built ammunition magazines on the two Indian mounds within the fort.
After the fall of Memphis in June 1862, Union forces used Fort Pickering as a major supply depot and staging area. Gen. William T. Sherman increased its size so that it extended for more than a mile along the river and a third of a mile inland. By 1864, with 102 cannons in place and more than 10,000 soldiers, Fort Pickering was the strongest military installation on the Mississippi River.
When Federal troops occupied Memphis, hundreds of slaves from Arkansas and Mississippi fled their plantations to work for the army at Fort Pickering. The government established Camp Shiloh in 1862 and Camp Fiske in 1863 south of the fort to provide housing, churches, and schools for the families of these men.
Many of the former field hands and laborers, known as contrabands, clamored to join the Union army. By December 1863, nearly 1,200 African Americans had enlisted in the 3rd United States Colored Heavy Artillery Regiment. They manned the huge guns that protected the river approaches to Memphis and performed guard detail and other military duties. Col. Ignatz G. Kappner commanded the predominantly black garrison at Fort Pickering until the end of the war.