Lord Voldemort was conquered on May 2, 1999. It wasn't for almost a full year later (January 8th, 1999) that all the Death Eaters were rounded up and sent to Azkaban, and then the war was finally over.
Hermione found out that she was pregnant shortly after the war, and she and Draco got married the day after Valentine's day. Two years later, they had yet to get the recognition they deserved and decided to just leave England.
Hermione Malfoy became a famous Hit Witch for the American Ministry, also known as MACUSA, and her husband Draco became the owner of many hotels and businesses worldwide. They had two kids, Scorpius Orion and Lyra Ruby.
Harry and Ginny Potter searched for their friends for almost 4 full years, but never thought to check in America. Ron Weasley never got married, thinking that one day, maybe at the 15 year Hogwarts reunion, Hermione would come back and they could be together.