3. HENRY & JOHN
In Season 8, we learned about Henry Winchester, father of John and a member of Men of Letters. He completed his final initiation ceremony and was given an assignment which proved to be his last. Even though he was extremely terrified that if anything were happen to him then he would leave his wife widow and John without a father. John grew up believing that his father deserted him, a cycle that he would repeat with his own sons. When Henry learned about Dean and Sam being his grandkids, Dean revealed to him that all this time John thought that he walked out on him. Henry realized that he would never make it back. At one point, John Winchester mentioned that he comes from a family of mechanics, but there was no proof of Henry being a mechanic.
2. RESURRECTION
A thing about the Winchester is that nothing could stop them, not even death. They have an old habit of cheating the death. It makes them special. Both Sam and Dean have died numerous times throughout the show, but have been resurrected plenty of times. Azazel killed John Winchester forty years ago, but due to the deal of Mary, he was resurrected. Mary Winchester died at the hands of Azazel, but she was resurrected by Amara in Season 11 as a token of gratitude to Dean. Then we have Adam who died at the hands of ghouls, but the angels resurrected him because he was supposed to be the vessel of the archangel Michael. Jack who is the honorary member has also been resurrected after he died and went to Empty. The only male member of the Winchester family is Henry who has not been resurrected. His death became permanent.
1. JOHN WINCHESTER
Did you know that in the earlier drafts of the show, John was originally named Jack and his last name was Harrison. Both John and Mary were supposed to die in a car crash which would be caused by demon. John would survive the crash, but Mary won’t. Despite having numerous family members from his wife’s side, John didn’t remain close with any. He had a son from another relationship named Adam. He kept it a secret and continued supporting Adam, spending time with him. According to Dean, he saw Adam as his second chance to raise a child in a normal fashion, to do something that he failed to do with Dean and Sam.