Heraldic visitations cover the Tudor-Stuart Period of English history. Like modern-day "Who's Who" publications, these records provide information regarding well-known people of their time. Officials generated these records in order to trace pedigrees and relations of armigerous1 families. Many Americans of British descent can tie into these families through disinherited "second sons."
Historical societies have published the majority of early English heraldic visitations. Some of these pedigrees have not made it to the press, and can only be accessed in county record offices and library special collections in the British Isles. They often trace family pedigrees back to medieval roots covering a time period for which few written records have survived. Visitations are usually county-wide in scope.
Mark D. Herber in Ancestral Trails: The Complete Guide to British Genealogy and Family History2 provides an excellent explanation of the process involved in creating heraldic visitations:
Visitations were undertaken by heralds in each English county (at intervals of approximately twenty or thirty years) between 1530 and 1686, in order to record the use of coats of arms. . . . For each county, the sheriffs compiled lists of nobles, gentry, knights and gentlemen, who were then called before the Heralds to show the arms that they were using and prove their entitlement (by grant or long use) to those arms. . . . Much of the information submitted to the Heralds was oral tradition of the family (sometimes unreliable) backed up by monuments in the local church or documents in family archives.
The Family History Library in Salt Lake City holds copies of heraldic visitations from every historic English county. The only exception is Monmouthshire which switched hands back and forth between the nations of Wales and England during past centuries. To find these records on the Family History Library Catalog, search on the county/shire level under the category VISITATIONS, HERALDIC.
Many families, in addition to those who currently hold coats of arms according to the right of primogeniture, descend from the families discussed in these volumes. Genealogists should investigate every surviving register for possible ties with ancestral families.
1 Armigerous: adjective denoting possession of a coat of arms. Derived from the Latin term armiger, which translates to English as esquire.
2 Mark D. Herber, Ancestral Trails: The Complete Guide to British Genealogy. (Baltimore: Genealogical Publishing Co., Inc., 1998), 494.