Searching deeds requires the researcher to look for a time after the actual document was drawn up and signed. Purchasers usually recorded deeds relatively promptly, but not always. If the courthouse was a distance or difficult to get to, it may have been years before the document was recorded. And sometimes people simply forgot to record a deed and did not realize it until the property was sold or the owner died. Don’t assume that your ancestor who lived in an area from 1830-1840 would have no deeds of sale recorded outside that time frame.