Adam was born presumably on his family's farm in that part of Virginia that is now Grant Co., West Virginia. There he married Rachel Michael. Like the parents of both, Adam and Rachel were founding members of the Brethren congregation at Greenland Gap.
Adam was buried on the family farm just west of Rt. 42 close to the "Brick Church" near Maysville, Grant Co., West Virginia. This property was the home of Adam Cosner's nephew Simon Idleman at the beginning of the twentieth century and of Idleman's granddaughter Dorothy Browne in the latter years of the century. (Bio by Mark Hale, citing RETURN TO GREENLAND)