Seeking birth records prior to 1800 in Maryland

I have the death certificates for my great-great-great grandfather and his wife, they both died January 23, 1891 in Washington D.C. after being hit by a B&O Railroad train. What I can't find are any birth records for either of them or record of their parents. His name was James Owens born between 1811-1813 in Maryland, either Montgomery or Prince Georges Counties, his wife was Nancy A. Raleigh (or Rally) and she was born approximately 1816 or so. I have been able to piece together that they ran a dairy farm near South Brookdale in Montgomery County, Maryland, but nothing else. I do not know what church the family would have attended, but I would guess they were Methodists since that is the denomination my great grandmother was raised in. I would appreciate any help or guidance on where to look. Thanks