Ever watch Mr. Rogers when you were a kid? He used to sing that song when he opened his program every day. My two kids would walk around singing that little song for hours after the show would go off.
Sometimes when you have an elusive ancestor searching for those you know lived around him may be the best way to locate him.
When people migrated to another country or just another state they usually didn't move alone. Unlike today where many families just pick up and move leaving everyone behind, usually in our ancestors time, many of the families in the neighborhood went with them.
When searching for your elusvie ancestors be sure to make notes regarding who lived next door, or even down the block. Those were the people who helped put up barns, helped with harvesting crops, birthing babies, and any other crisis that came along. Often marriages were arranged between neighboring families as well.
When you are doing the census for your families look for females from your family among the neighbors. Sometimes they have married and may be living down the street or even next door, married and raising her family on a nearby farm, children left behind by the death of a father often ended up being indentured out to neighbors or simply apprenticed out to neighbors to learn a trade or profession.
Keep in mind that the neighborhood was like a mini country - the survivival of one often meant the survival of all - so whether you are searching for clues to the whereabouts of a missing ancestor or a married daughter, take a few minutes and check out the neighborhood. It just might be the solution to your problem.