"Jesus in America: Personal Savior, Cultural Hero, National Obsession" by Richard Wightman Fox (HarperSanFrancisco, $27.95).
"American Jesus: How the Son of God Became a National Icon" by Stephen Prothero (Farrar, Straus, and Giroux, $25)
One of the staples of American humor is the "three proofs that Jesus was..." joke, whose completion is always an ethnic identifier.
Thus, three proofs that Jesus was Jewish:
1. He went into his father's business.
2. He lived at home until the age of 33.
3. He was sure his mother was a virgin, and his mother was sure he was God.
Interestingly enough, this ongoing joke series includes no entry headed, "Three proofs that Jesus was American." Only in a country like Israel, where "American" names an ethnic group within the nation, could such a joke be told. If such has been told, I hope somebody will be kind enough to send me the three proofs.