John D. Wagg, son of minister James Wagg, was born in Jefferson, North Carolina, on July 8, 1835. Although he initially studied medicine in 1854 at Jefferson Academy, Wagg eventually entered the ministry. On July 17, 1858, the Holston Conference of the Methodist Episcopal Church South authorized and licensed him as a preacher. The Holston Conference, in the mid-nineteenth century, encompassed most of western North Carolina, eastern Tennessee, and southwestern Virginia.

Wagg's first appointments were in the Virginia counties of Giles, Russell, and Wise, where he labored as a circuit preacher. By 1859, however, he was reassigned to Hillsville, Virginia, where he married Lavinia "Vin" Anderson on May 13, 1862.

Wagg subsequently assumed ministerial duties in Asheville, North Carolina, in late 1862. His only child, Martha Elizabeth "Bettie" Wagg, was born there at the home of lawyer Joshua Roberts on March 6, 1863. On August 6, 1864, his wife Lavinia died.

In late 1864, John D. Wagg relocated to Bristol, Virginia, although he continued to deliver occasional sermons in Asheville. Wagg was superannuated by the Methodist Episcopal Church South in 1865 because of tuberculosis. He died in 1866.

Bettie Wagg attended Martha Washington College in Abingdon, Virginia, in the mid-1880s. She died on March 20, 1898, and is buried along with her father John D. Wagg in Hillsville, Virginia.