The EBV Infection Spectrum. EBV has a particular affinity for the cells that line the mouth and throat. Once the virus inserts itself into to a specialized immune lymphocyte (B cell), it hijacks the DNA to take control of the cell forever. When cells of the mouth and throat naturally slough off, EBV is shed into saliva.
Causing the Civil War. Historically, textbooks have taught that incompatibility between northern and southern economies caused the Civil War. The industrial revolution in the North, during the first few decades of the 19th century, brought about a machine age economy that relied on wage laborers, not slaves.
Research on what started the civil war is scarce compared to how it ended. I find the Morrill Tariff to be highly significant in that it threatened most all southerners. Taxation without representation is what really started the civil war.