David Edward (D. E.) Brown was born October 27, 1879, in Prince George's County, Maryland, to Mary and David Brown. According to the 1900 census, David Edward had an older brother, John, and seven younger sisters: Lidie D., Gertrude, Lena, Mary, Maggie, Bertha, and Nellie. In 1890, the census taker listed David Brown, Sr., as a railroad worker and in 1900 as a farmer. At the age of twenty, D. E. Brown matriculated to the Maryland Agricultural College (MAC). He remained a student at the college until 1904, playing both baseball and football, thus becoming a life member of the "M" Club.
Dr. H. J. Webber, head of Plant Breeding in the Bureau of Plant Industry, appointed Brown as a Special Field Agent for the U. S. Department of Agriculture on July 1, 1906. Brown was headquartered at the Maryland Agricultural Experiment Station in College Park until 1908, when he transferred to the experiment farm at Upper Marlboro, Maryland. Employed by the USDA for forty-three years, Brown's major research concerns were tobacco improvement, breeding, and culture. In addition to writing articles about tobacco fertilization, cropping systems and types, and varieties of Maryland tobacco, Brown was part of the team, headed by Dr. W. W. Garner, that developed the Maryland Mammoth variety of tobacco, which later became the variety used in extensive research on photoperiodism, the response of plants and animals to the amount of daylight in twenty-four hour periods.
On May 19, 1931, he married Alberta Smith of Easton, Maryland, and the couple had one child, David Edward. Some time in the 1920s, Brown purchased Mount Calvert, an estate reportedly built in the late eighteenth century and the only building remaining of Charles Town, the original county seat of Prince George's County. At his death on March 11, 1970, Brown was survived by his wife, son, one grandson, and four great-grandchildren, including David Edward Brown IV.