The Importance of Going One Step at a Time
My wife's great-grandfather is William Apgar, born around 1888 in Chicago. I spent hours looking at Apgar families in 1880 and in 1900 (and in city directories), trying to get an idea of who his parents could be.
Turns out Apgar was not his last name after all--it was a last name he took upon his marriage for reasons I am not entirely aware of. His marriage record and a 1910 census enumeration, along with some other information made it clear that his name at birth was actually William Frame. All that time spent looking for Apgars was for naught. Had I worked on him in more detail initially in the 1909-1920 time frame, I would have realized this and not spent so much time looking for the wrong family.
And for those who wonder if Apgar was a name in William's background, the answer is no. It appears he simply chose the name from somewhere other than his own family history.