John Cloyd Emmerson was born on 6 July 1891 at his family home on 509 Dinwiddie Street, Portsmouth, Virginia to parents John Cloyd and Claudia Mildred Emmerson. His family is traced family back to prominent Virginia families of the Cockes of Bremo and the Barron family who distinguished themselves in the formation period of U.S. Navy. Emmerson grew up and was educated in public schools in Portsmouth. He got his first job working at his father's insurance agency and union ticket office. Like so many young men at the outbreak of World War I, he joined the US Army and was sent to France with the 1st Depot Division. Emmerson came home to Camp Dix in 1919 and was honorably discharged as a Corporal. He came back to Portsmouth and rejoined his father's business as a partner. Emmerson later joined The Independent and The Daily Advocate in Elizabeth City, North Carolina, in 1928 to 1933. He settled down with A. G. Pinkston and Company of Portsmouth as an office manager from 1940 until 1958 when he finally retired.

Emmerson never married, however stayed busy researching his own family genealogy and writing about local history. He compiled and published The Steamboat Come to Norfolk Harbor in 1949, Stream Navigation in Virginia and Northeastern North Carolina in 1950, and The Chesapeake Affair of 1807 in 1954. His passion for local history and his generosity greatly enhanced the local history collections at both the Norfolk and Portsmouth Public Libraries. He passed away on 3 Feb 1980, in Portsmouth, Virginia, and is buried beside his family in Oak Grove Cemetery, Portsmouth, Virginia.