Let me say they are a few William Dunlap, (Dunlop) and it didn't really give me any dates of birth. But let me tell you what I found so far, and if you need any other information please let me know.
Sarah Franklin Dunlap - christening 2 Feb. 1768 Christ Church and Saint Peters. Philadelphia, Philadelphia, PA, father - William Dunlap and Elizabeth Dunlap.
Fanney Dunlap - Christening 21 May 1760 - Christ Church and Saint Peters. Philadelphia, Philadelphia, PA. Father - William Dunlap and Deborah Dunlap.
William Dunlap married 2 Feb 1806 to Isabella Strachan in Philadelphia, PA.
Stillborn Male Dunlap 17 June 1871 Philadelphia, Philadelphia, PA Parents William Dunlap and Margaret Dunlap- address 183 S. Sepirra Woodlands Burial 19 June 1870.
Charles Dunlap Death 12 May 1861 Philadelphia, PA Parents: William Dunlap & Jane ?
William H Dunlap died 11 Oct 1871 Philadelphia, PA Father William H and Rebecca F. Dunlap
Dunlap - male died 17 Sept 1846 Philadelphia, PA Father John Dunlap.
I found all of this on Familysearch.org. But you can also go to genealogyintimemagazine.com and put in the Dunlap name and get more info. Just let me know if you need more info. I don't know if I gave you any help or not, But I tried getting through the marriage records but wasn't sure where they married and it could be that they misspelled his name.