As you research your family history, don’t forget to consider “collateral” relatives—i.e., your ancestor’s brothers and sisters, aunts and uncles, etc.  While the information you can find on your direct ancestor may be sparse, you never know what kind of amazing family history treasures these “collateral” relatives may have left behind.

Here’s a great example by Donna Potter Phillips that illustrates this principle:

“I was a quick convert to the principle of doing Collateral Research, or doing Whole-Family Research, as I prefer to call it, when my student found the obituary of Ann Oswald.  Let me explain.

“We’d worked on her family history and pretty well documented her Oswald line back to one Eleazer Oswald, of colonial Pennsylvania.  This is a difficult surname to research, and we’d not found much on this elusive ancestor.

“Eleazer apparently had married, for he had four children, but (of course) the wife’s name was unknown.  The second son, James, was my student’s ancestor, and we had found a bit on him.  Scanning the family group sheet she’d compiled, I asked how much work she’d done on James’ sibling.  ‘None,’ was the answer, ‘they’re not my line.’  This was a Teaching Moment ready to happen, and I jumped right in.

“To shorten this story, we began looking for any and all references to James Oswald’s siblings.  My student really balked on one name, James’ sister Ann, for Ann had never married, so never had any children.  ‘She died an old maid; what can we possibly learn from her records?’ said my student.

“When we found the obituary for ‘Miss Ann L. Oswald,’ who died at age 91 in Philadelphia, it contained a lengthy biography of her father, Col. Eleazer Oswald!  My student was both disbelieving and thrilled.”

Here’s the obituary they found:

“Miss Ann L. Oswald was the daughter of Col. Eleazer Oswald, who, during his time was one of the most prominent men in Philadelphia.  An Englishman, of a good family, he sympathized with the Americans in the preliminary controversies with Great Britain before the Revolution.  He came to America in 1770.  Her served under Arnold in his invasion of Canada, was captain at the capture of Ticonderoga, and led the forlorn hope at Quebec, where he was wounded in 1775.  He was Lt. Col. of Lamb’s Artillery Regiment in 1777, was commended by Knox and Lee at the Battle of Monmouth, and shortly afterwards left the service, when he came to Philadelphia and established the Independent Gazetteer, which, by his ability, he made the leading journal of the time.  He entered into business as publisher and printer, and was public printer for the State of Pennsylvania.  In 1789 he challenged Alexander Hamilton to fight a duel, but the meeting was prevented.  In 1792 he was in England, went over to France, joined the French army, in which he fought as colonel of a regiment of artillery at the Battle of Jemappes.  Subsequently he returned to this country and died in New York of Yellow Fever on October 1, 1795, aged 40.”