The Common Sense Book of Baby and Child Care 50 million

One of only three nonnovels on this list, The Common Sense Book of Baby and Child Care by Dr. Benjamin Spock unrelated to the Star Trek character of the same last name was published in 1946. The bestselling book in America during the 20th century, this tome was written for parents, especially mothers, as a manual on child care. PostWorld War II, Baby Boom mothers found great relief in Spocks uncomplicated, supportive tone.