There are several John W Bakers from this area in VA on familysearch.org. You might want to look at the various data and see who matches.
Jno W Baker
U S Census 1860 Loudoun, Virginia
birth: 1852 Loudoun
Jno. W. Baker
birth: 1852 Loudoun Co., Va.
marriage: 30 Nov 1875 Loudoun, Virginia
parents: Jos. C., Mary J.
spouse: Sarah A. Fry