Here is an important finding aid for genealogists in search of their Civil War ancestors and for Civil War researchers in general. It is nothing less than a catalogue of 2,260 engagements between Union and Confederate forces fought in Confederate territory throughout that great conflict. Based on the records of the U.S. Surgeon-General, various maps and atlases, and a re-working of information found in the "Statistical Record of the Armies of the United States," by Frederick Phisterer (1883), "Infestation of Yankees" features a tripartite index to every skirmish in which Union casualties occurred--no matter how few. Each of the three indexes gives the place name of the engagement, the date, and the county and state in which the battle site can be found. To anticipate virtually any researcher's requirements, Dr. Bahn has arranged the skirmishes/battles first chronologically by the date of the engagement, then alphabetically by state and thereunder by place name, and finally by state and thereunder by county. Thus, for example, someone searching for an ancestor who served as a Union soldier in various engagements will be guided to the counties or dates of those conflicts, while an ancestor hunter looking for an antecedent who lived in the vicinity of various battles can determine all the possible engagements in which the ancestor might have fought. Supporting Dr. Bahn's tripartite index are a number of engagement and occupation maps shedding light on the movement of Union troops throughout the Confederacy, as well as a table listing Confederate cities with populations in excess of 2,000 persons in 1860.