Edward Otho Cresap Ord began his military career after graduating from the United States Military Academy in 1839. He was commissioned in the 3rd US Artillery, and sent to Florida to participate in the Seminole Wars. After his service in Florida, he was sent, along with William T. Sherman and Henry Halleck, to serve in California. They participated in the construction of forts, as well as surveying of the area that would become Los Angeles.
At the outbreak of the Civil War, Ord was sent back east and made a brigade commander of the Pennsylvania Reserves. On May 3, 1862, Ord was promoted to major general, and was commanded to lead the 2nd Division of the Army of the Tennessee. He missed serving during the Battle of Corinth, but took part in the end of the Siege of Vicksburg. He briefly commanded the XIII Corps with the Department of the Gulf after which he went to the eastern theater in 1864 to command the XVIII Corps. During the Battle of the Crater, while Ord’s forces were available, they did not actively participate. In late 1864, Ord and his Corps participated in an attack on Fort Harrison, where Ord was seriously wounded. He returned to service in January of 1865, and took command of the Army of the James during the Appomattox Campaign. His men served a crucial role in the Union breakthrough at Petersburg. At the end of the campaign, Ord ordered a forced march which relieved General Philip Sheridan and his men, and helped force Robert E. Lee to surrender.