I've been asked this question more times that I can remember . . . and can't say there was one 'single' spark, but there were certainly a few very important events that contributed significantly to my own family history pursuits. The first one that comes to mind was the airing of Roots on American television in January 1977. At the time, I was just 14 years old and a Freshman in high school. My parents, four siblings, and grandmother all watched the series each night. It raised many questions for me about the history of our country, slavery, but also about the arrival of my own ancestors from Ireland and Italy. Hard to believe that was nearly 34 years ago - seems like yesterday in some ways. At that time, there was just one television in the home and even then we had basically 3 channels - ABC, NBC, and CBS. If you wanted to change the channel, you actually had to get up out of your seat and turn the analog dial (or have one of your kids do it for you, ha).
I wonder if I had video games, the Internet, a cell phone with texting or any of the other 'wonders' of modern technology, I wonder if I would have even watched Roots at all? Probably not. It turns out to be a good thing that it aired how it did, when it did. Today, programming barely stands a chance. One or two episodes, a peek at the ratings, and it's thumbs up or thumbs down.
Two other things that come to mind that sparked my initial interest were the American Bi-Centennial in 1976 and, for me, two years earlier in 1974 was the Tri-Centennial celebration in my home town, the city of Waterbury, Connecticut. Both those events were surrounded with non-stop nostalgia and looking back, so it was perhaps only natural that these three things combined led me down the path of addition toward genealogy.
Share your story - I'd love to read who inspired you and/or what events helped jumpstart your family tree.