If a builder or repairman were seeking payment for work performed, he may have filed a mechanic's lien at the courthouse which may give useful information about the work that was completed. Libraries and other research facilities including the contents of attics, may contain much valuable information about the historical framework of the community and, sometimes, about features of a particular building's history. County histories and other such publications should be consulted. Old prints, drawings and photographs are useful in determining the original aspect of specific buildings, neighborhoods, and districts. Such sources, if dated, can also help to pin down the date of construction more closely.
County atlases and maps for civic improvements can also be quite useful.
Genealogical files and other special collections may also be of assistance. But memory is a fragile faculty and should not by itself be relied upon to substantiate the property's history. Experts on local history should be sought out whenever possible since they may be in possession of material or knowledge that will be relevant to your research project. Finally, experts in architectural history should be consulted whenever possible since these persons have knowledge about past architectural trends and developments that may help you to understand the building better. Most important, an architectural historian can assist in giving you a fair estimate of the building's architectural significance, an evaluation that is very difficult for the layman to make.