The chief interest in this work rests with the naturalizations in Part III, which were compiled from Maryland's Provincial Court documents in the Hall of Records, Annapolis, Between 1742 and 1775 upwards of 1,000 naturalizations were granted in Maryland. Data in the naturalization records presented here includes the identifying number of the record, date of naturalization, date of communion, volume and page of the Provincial Court Judgments, name, county or town of residence, nationality, church membership, location of church, and witnesses to communion. Place names, clergy, and parish locations are identified in the appendix.

Containing political, historical, geographical, scientifical, statistical, economical, and biographical documents, essays and facts: together with notices of the arts and manu factures, and a record of the events of the times.

The major part of this work is an alphabetically arranged and cross-indexed list of some 20,000 Maryland families with references to the sources and locations of the records in which they appear. In addition, there is a research record guide arranged by county and type of record, and it identifies all genealogical manuscripts, books, and articles known to exist up to 1940, when this book was first published. Included are church and county courthouse records, deeds, marriages, rent rolls, wills, land records, tombstone inscriptions, censuses, directories, and other data sources.

About two-thirds of this work is devoted to a history of the land administered by colonial Maryland, with a detailed inventory of Patents, Warrants, Proprietary Leases, Rent Rolls, Debt Books, etc. The remainder consists of a study of the colonial Prerogative Court, which had control over probate matters.

St. Mary's residents played a key role in the development of the Catholic Church throughout the whole of America, providing the spearhead of the westward expansion of Catholicism. In 1785, for example, the first of many Catholic families from St. Mary's crossed the mountains to find land in Kentucky, while a few years later, driven by economic necessity, others migrated to Georgia, Missouri, Louisiana, and Texas. Mr. O'Rourke has collected many of the earliest surviving records of the Catholic families of St. Mary's County, Maryland. The most significant portion of the work contains the marriages and baptisms from the Jesuit parishes of St. Francis Xavier and St. Inigoes, which, in the case of baptisms (1767-1794), give the names of children, parents, and godparents, and the date of baptism; and in the case of marriages (1767-1784), the names of the married partners and the date of marriage.

This work contains previously unpublished Revolutionary War records and consists chiefly of the names of those who subscribed to the Oath of Fidelity and Support from the early counties of Calvert, Frederick, Montgomery, and Washington. In addition, there is an extensive list of loyal civil servants of Prince George's County-constables, surveyors, justices, grand jurors, etc. The data, embracing details on some 5,000 persons, derive from manuscript source records in both public and private collections and cannot be found elsewhere in print.