The brothers couldn't have been more different, family and friends said. Jim was bigger, louder and impulsive. John was earnest, focused and disciplined.
"John wasn't near the athlete that Jim was, but he had this quiet dignity about him," said Tim Anderson, a teammate at Pioneer High School in Ann Arbor. "John was hard-nosed, no-nonsense and extremely bright.
"The fact that he wasn't a star athlete like his brother didn't bother John, and you never thought of him as being in Jim's shadow."
John, a defensive back, was meticulous to a fault, Anderson recalled.
"Once, after practice, we were in the showers when John told me, 'You should always wash your hair first, because otherwise the stuff in your hair will get all over you and you'll have to wash again,' " said Anderson.
"John always thought about the right way to do things."
That anecdote is typical of her son, Jackie Harbaugh said.
"John figures out what works best in every situation and then works to make it right," she said.
What he lacked in talent, Harbaugh made up for in smarts.
"Even then, he was a coach on the field," said Greg Yarrington, another teammate in high school. "He knew what was going on and had the ability to help others in the game with their coverages and their reads."
For one year, the Harbaugh brothers played together in high school: Jim, the hotshot sophomore, and John, the soft-spoken senior.
One game in particular stands out in Jackie Harbaugh's mind.
"It was a Friday night in October, and John went in to play receiver," she said. "The next minute, I heard on the loudspeaker, 'It's a pass, Harbaugh to Harbaugh!'
"Life doesn't get any better than that."
Diverse friendsAs a teenager, John Harbaugh was color-blind in an era when race was still an issue, said Yarrington, who is black.
"He didn't make a distinction about folks. Some of us from the other side of town were a little rough, but John embraced us for what we were," said Yarrington. "He had a diverse set of friends which has probably carried over into his coaching."
For several summers, said Yarrington, Harbaugh singled him out to join him at a retreat for the Fellowship of Christian Athletes, where campgoers weren't allowed to cuss, drink or talk trash.