Most people are familiar with the U.S. census, but did you know that federal census takers have been going door-to-door asking questions of American families since 1790? Although it is instituted and maintained primarily to track the nation's population for government planning, a census is among the records that genealogists refer to most frequently because it captures detailed information on an individual or family at a particular point in history — essentially a once-per-decade snapshot of the country's inhabitants. Begin with grandpa or great-grandma in the 1930 census, and you may be able to use the clues you find there to march your family all the way back through census records to 1850!