If you know where your ancestors lived in the late 1800s, professional genealogists can sometimes find maps of the town with their names on their lot. Some like Ontario for example that shows every family in the town. This helps build a profile for your ancestor that includes their neighbors and possible some migrating friends that may provide clues or affirmations of their origination. Here is a link to New England, Pennsylvania and New York maps: http://www.oldmapsne.com/
