I found your William Morrow in the 1860 census Pn, Cumberland Co, Southampton, Shippensburg, pg 687: Morrow, William age 32 born Pa, shoemaker; wife Ann 31 born England; Susan 8 born Pn; Ann 5; Margaret 3; John 2; Emily. Since William is shown age 32, his birthyear would be c1828.
Since you are interested in William's parents, other Morrows in 1860 Cumberland Co Pa census: Samuel Morrow age 59 pg 708, Thomas Morrow age 69 pg 708 occupation Carpenter, and John S. Morrow 69 Newville pg 555 all are old enough to be William's father, but Samuel lived adj to another William Morrow age 42, so I favor Thomas as a likely candidate for your William's father.
I looked page by page thru the 1850 Pn Cumberland, Southhampton census, didn't find any Morrows.
1870 your William appears in Cumberland, Southampton, pg 461: Morrow, William age 48 born Pa, occupation shoemaking; Ann 40; Anna 17; Margaret 14; John 13; Emma 11; William 10; May 3.
Thomas Morrow, age 80 lives at Hopewell pg 109, carpenter.
Since William's age is 48, his birthyear would be 1822. This makes a range of 1822-1828 for his birth, in addition, you show 1817 for his birthyear.
Since the 1850 census of Southampton, Cumberland county didn't show any Morrows, you need to look over other parts of Cumberland County for your William who should be age 22-33 in 1850 & probably not living with his parents, but most likely living nearby them. I can't do this. If you don't have a subscription to Ancestry.com, then go to a nearby genealogical library and see if they have an 1850 census index book on Pennsylvania by surname. If they do, look up all Morrow families listed in Cumberland county using info from the book & hopefully you'll find your William and his parents nearby.
Bill Morrow Co-Administrator Morrow DNA testing project
DNA Project homepage:http://freepages.genealogy.rootsweb.com/~amorrow/morrowdna.h...