Henry Hardon's book Newington, New Hampshire Families in the Eighteenth Century mentions Samuel and Elizabeth's marriage and also lists their twelve children.
William Shackford (1748-????)
John Shackford (1749-1816) - married Ruth Webb Adams
Samuel Shackford (1752-1843) married Nancy Walker
Seth Ring Shackford (1754-1777) - killed in action in Saratoga
Susanna Shackford (1756-1848) married Hatevil Nutter
Mary Shackford (1759-1825) - married Mark Walker
Elizabeth Shackford (1761-1843) - married William Walker
Abigail Shackford (1763-????)
Hannah Shackford (1764-1811) - married Jethro Furber and Benjamin Coleman
Josiah Shackford (1767-1843) - married Lydia Dennett
Nathaniel Cooper Shackford (1769-1852) - married Phebe Nutter
William Shackford (1771-????)
We're still researching Samuel but have found records documenting that he was a constable, was elected selectman in Newington, was a Captain in the militia during the American Revolution, and signed the Declaration of the Inhabitants of New Hampshire in 1776. We also know that when Samuel was 44, his father died leaving him 1/2 the estate in Newington, 1/2 the real estate in Portsmouth, 1/2 of 1/2 of a Pew in the North Meeting House in Portsmouth which William's wife had use of, 1/2 his personal estate in Newington, a gun, pistols, Burkets, Annotations in the Bible, a watch, his father's wearing apparel, and 1/2 the right in Nottingham. More about Samuel at a future date!
Hardon Henry W, Newington, New Hampshire Families in the Eighteenth Century (Bowie, Maryland: Heritage Books, Inc, 1991), page 168
The New England Historical & Genealogical Register. For the Year 1868 Volume XXII: Published Quarterly, Under the Direction of the New England Historical Society (Boston: David Clapp & Son, 1868), page 26; digital images, Google Books (http://books.google.com : accessed 28 February 2014; Church Records of Newington, N. H.
New Hampshire, County Probate Estate Files, William Shackford Case 3981; "New Hampshire, County Probate Estate Files, 1769-1936," digital images, Family Search (http://www.familysearch.org: accessed 25 April 2014); Rockingham, Case no 3836-3988 1771-1773, Image 1460-1474