I never heard Newt was adopted.
“”My father grew up as a very angry person. When he signed up for the navy, the recruiting officer said, ‘Why did you fill out your application wrong?’ He said, ‘What do you mean?’ And he said, ‘You put your grandmother’s name in where your mother’s name should be.’ He found out that he had been born out of wedlock. They never told him. Talk about being outraged!”
The saga continues: “Big Newt was physically enormous. Six foot three, and could use a nine-pound sledgehammer with one hand. I’d say from the time he was 16 to 35 he was in bar fights...My mother was very frightened of him. So she decides to file for divorce. He tries to talk her out of it, fails, scares her even more, so she divorces him and then marries Bob Gingrich, who is also adopted...So that’s the background, and people assume I’m some right wing, out-of-touch Neanderthal who doesn’t get it. I mean, I’m adopted! Both of my fathers are adopted! I mean, give me a break!”
Confusion over his identity was a recurrent theme in Newt’s boyhood. “I did not use the word ‘stepfather’ until I was talking to Marianne in 1982,” he says. “I had a very confused blockage in sorting out the relationships.”
“A heck of a mess when you think about it,” Gingrich’s mother, Kit, says reviewing the past. Big Newt, having been abandoned by his real father, Robert Kerstetter, was taken in by Newton and Hattie Belle McPherson and raised in a household where his real mother, Louise Kepner, was passed off as his sister. Bob Gingrich was a foster child, not adopted until he was 16. It sounds like a Faulkner saga. In Pennsylvania.”
http://www.pbs.org/wgbh/pages/frontline/newt/vanityfair1.html