Daniel Cloud was born on June 29, 1837 in Warren County, Virginia. He entered Dickinson College, where he was a member of the Phi Kappa Sigma fraternity and the Belles Lettres Literary Society. He graduated with the class of 1858. From 1858 to 1859 Cloud taught at Charlotte Hall, Maryland, and from 1859 to 1860 he taught at Salina, Alabama. In 1860, he accepted a position at the Biblical Institute in Conrad, New Hampshire.
With the start of the Civil War, Cloud returned to Virginia where he joined the 7th Virginia Cavalry under Captain Ashby. After being promoted to captain in 1863, he transferred to the Secret Service of the Confederacy. Under the command of his college roommate, Captain Thomas N. Conrad, Cloud helped to coordinate Confederate spies in Washington, D. C. and the transportation of intelligence to Richmond. At one point Cloud and Conrad planned to abduct President Lincoln, but their plans fell through.
After the war, Cloud became superintendent of public schools in Vicksburg, Mississippi in 1865. He was later admitted to the Bar in Vicksburg, where he remained for the rest of his life. Daniel Mountjoy Cloud died on May 31, 1871.