The title,"After Twenty Years," is at the heart of O. Henry's narrative. For, two old friends who separated in their youth have agreed to meet each other in front of their favorite restaurant. When the policeman asks the man standing in this doorway why he is there, he states,
"Twenty years ago to-night...I dined here at 'Big Joe' Brady's with Jimmy Wells, my best chum.... He and I were raised here in New York, just like two brothers....The next morning I was to start for the West to make my fortune. You couldn't have dragged Jimmy out of New York....Well, we agreed that night that we would meet here again exactly twenty years that date and time, no matter...what distance we might have to come.
It is the meeting of the two old friends after twenty years that causes the conflict of the story because Jimmy Wells is now a policeman while Bob has become 'Silky Bob,' a criminal who is wanted in Chicago. When Bob strikes a match, Patrolman Wells recognizes his old friend and realizes he is a wanted criminal. But, "after twenty years," he does not have the heart to arrest his old friend; consequently, he sends an undercover man to arrest his own friend who stands waiting in the doorway of the former restaurant; this undercover policeman carries a letter from an old friend explaining why he could not meet his old friend Bob.
Twenty years is a long time. It is long enough for people who were once young to become middle aged. In this story, two friends were basically still teenagers when they went their separate ways. They had not formed their life paths yet.
He and I were raised here in New York, just like two brothers, together. I was eighteen and Jimmy was twenty.
Bob clearly wanted to be rich. He tells the “cop” he meets on the street while waiting that he went west to make his fortune. The fact that Bob left and Jimmy stayed tells you about both of their personalities. Bob was ambitious, and wanted to be rich. He’s the one that left. Jimmy, on the other hand, was satisfied with who he was. He stayed.
It is not surprising really that Bob became a criminal while Jimmy became a cop. Jimmy is an honorable man though, and he has to ask another cop to arrest Bob for him because he doesn’t have the heart to arrest his old friend himself.
[Twenty years] sometimes changes a good man into a bad one…
The cop that arrests Bob, who has been impersonating Jimmy, tells Bob this. Going west is no coincidence. Throughout America’s history, the west has always been a place of opportunity. However, there has often been illegal activity there too. Bob went west to make his fortune by breaking the law, and Jimmy stayed behind and became the law.