Deeds as genealogical evidence
A deed transfers real property. The body of a deed names the grantor (seller), the grantee (buyer), the consideration (price), a description of the property, and the witnesses. Family relationships appear explicitly in deeds of gift — a father deeding land to a son 'for natural love and affection' — and implicitly in partition deeds, which divide an estate among heirs and name each one.
Land was often the only substantial asset a family had, so deeds fill gaps where no will was written. A series of deeds from widow and children selling their shares of inherited land is a reliable substitute for a probate petition.
Patents and first ownership
A patent is the original grant of land from the government to a private owner. In public-land states (everywhere except the original 13 colonies plus Tennessee, Kentucky, Vermont, Maine, Texas, Hawaii, and West Virginia), federal patents from the General Land Office track first ownership. State-land states handled grants through their own land offices or colonial governments. Patent records usually include the patentee's residence at the time of the grant — a useful anchor when tracing westward migration.
Indexing conventions
Grantor and grantee indexes are kept separately, typically by the first letter of the surname and then roughly chronologically. When searching an index, check variant spellings and remember that a married woman's surname is her husband's — widows and heiresses appear under both. Deed books are numbered and paginated; a typical citation looks like 'Deed Book C, p. 214'. That's the address to photograph; the index entry is just the pointer.