His father, John Reeves Jones Daniel, served as an attorney general of North Carolina and member of the United States Congress.

In 1858, Daniel resigned his commission to begin a career as a planter in Louisiana, joining his father who had moved there following his last term in Congress in 1851.

Daniel was commissioned brigadier general on September 1, 1862, making him one of five men from Halifax County to attain that rank in the Confederate Army.

He spent the fall of 1862 with his brigade at Drewy's Bluff in Virginia and subsequently served in North Carolina, although his unit saw limited combat action.

Shortly after the Battle of Chancellorsville, he was transferred to Maj. Gen. Robert E. Rodes's division of Richard S. Ewell's Second Corps, where he served with distinction in the Gettysburg Campaign.

During the Battle of Spotsylvania Court House on May 12, 1864, Daniel led his brigade in a fierce counterattack on the "Mule Shoe" (also known as the "Bloody Angle"), trying to recapture the important position from elements of the Army of the Potomac, which had captured it at dawn.

The Junius Daniel Chapter of the United Daughters of the Confederacy of Weldon, North Carolina, was named in the general's memory and honor.