David's father, Peter, had bought a farm in 1830 in Mount Pleasant Township, Adams County, Pennsylvania, which is likely where David was born. Calculating from the ages accounted in his obituary and church burial records, David B. Smith has two possible birth dates. Using his death date of January 7, 1889, the New Oxford Item places his birth on March 25, 1832. The Conewago burial register records his internment as January 16, 1889, and lists an age that would place his birth on March 23, 1831, when using the death date from the newspaper. Unfortunately, no baptismal records could be located for him during that time period at Conewago Chapel, where his older and younger siblings were baptized.

Contributor Dennis Brandt (47232334 • [email protected]) notes that David served two terms of service in the Civil War:
1. State-drafted at the claimed age of thirty-three in Adams County October 16, 1862, mustered into federal service at Gettysburg November 5 as a private with Co. G, 165th Pennsylvania Infantry (aka "Drafted Militia"), and honorably discharged with his company July 28, 1863.
2. Federally drafted at the stated age of thirty-six, mustered into federal service at Chambersburg March 20, 1865, as a private with Co. C, 98th Pennsylvania Infantry, and honorably discharged with his company June 29, 1865. His draft notice is on page 4 of The Adams Sentinel, Tuesday, March 28, 1865.

David was a farmer in Mount Pleasant Township, Adams County according to the 1870 and 1880 US Censuses, where he neighbored his father, Peter, and his younger brother, Peter George. It appears that as Peter Sr. moved towards retirement, he must have sold parts of his farm to David, Peter Jr., and by 1880, to Francis.

"Jan. 7, in Mountpleasant twp., Mr. David B. Smith, aged 56 years, 9 mo. and 13 days." (New Oxford Item, New Oxford, Pennsylvania, Friday, January 25, 1889, Page 4)

"1889 Jany 16 David B. Smith 57 yrs 9 mos 15 days" (Conewago Chapel Burial Register)