I'm doing research for a historical fiction set in a small fictional town in America between the year 1778 and 1779. Let's say I have two characters, John and Jack. John is an officer in the Continental Army and (at the time of the story) a POW/prisoner of the state. He is relatively unpopular among the town people because the majority of the people in town are Tories and because he displays signs of PTSD, which is interpreted by some people of the town as insanity. Jack is a eight-year-old local of the town. Jack is tricked by his friends into believing he is cursed by John and only has a few days to live before John would come to him and brutally kill him. Thus, he decides to commit suicide before John can touch him, by drowning himself in a lake, drawing inspiration from a suicide he witnessed earlier. Just as Jack jumps into the lake, John gets to the lake and successfully saves him. There is no one around to witness John saving Jack, except for one woman who reports seeing John chasing after Jack.
Because of the lack of evidence and John's reputation in the town, some people who hold grudge against John are able to put pressure to have John arrested and put on trial. The reasoning behind this is that John intentionally chased after Jack to drown him. After John is arrested, Jack realizes he is lied to by his friends and wants to tell the truth of what really happened to save John. So my question is: in this scenario and setting, can Jack be eligible to tell his side of the story in court to save John?
I just can't find any good answer for my question. The closest answer to my question comes from this article, which states that England accepted child witnesses as early as 1778. However, I'm aware that during this time in America, there was a very strong anti-British sentiment and people basically rejected anything British-related. Plus, according to the timeline of my story, the decision of child witnesses would be a very new concept, and it might not come into effect in America during the same time period. So in the scenario that Jack is unable to testify in court, could there be any way that he can get the truth across to help John? (my story's goal is to have John walk free after the trial)