There are several Crowning Moments of Heartwarming in the show Liberty's Kids. Among them are:
The orphaned James's giving up of his mother's wedding ring, the only remembrance he has of his late parents, to make Sarah a new locket after her old one was lost, always makes this troper's heart melt. Just goes to show that despite her being a Loyalist and he being a Patriot, he truly cares for her!
"It is the greatest gift I have ever received!"
Also in The Intolerable Acts, after escaping from the redcoats, James thanks Sarah for covering for them... and then gives her his coat. Cue the fangirl squees.
The Marquis de Lafayette has a couple excellent moments, thanks to him being involved in two father/son relationships.
In his first episode "Lafayette Arrives", Lafayette fights in the Battle of Brandywine, which the Americans lose. When Washington goes looking for him and finds that he's been shot in the leg, Washington calls his personal surgeon over.
Washington: Treat him as if he were my son.
This one is doubly awesome because it happened in real life too.
He gets another one in "Valley Forge." Before he's supposed to leave to attack the British in Canada, General Gates tries to win him over and turn him against Washington. Lafayette promptly gives a toast to the general, tells Gates and Conway where they can shove it, and goes straight to Washington to warn him about it. The fact that he already knew does nothing to detract from this. This also happened in real life.
When France finally decides to side with the Americans, he and Washington share a Man Hug.
Lafayette's Crowning Moment comes in the penultimate episode "Going Home", early in which Henri overhears Lafayette telling Moses that he will be returning to France after one final visit to George Washington. Very upset at this, Henri runs out and tries to avoid Lafayette for the rest of the episode. A brief chase happens near the end where Lafayette follows Henri into the barn where he is hiding.
Lafayette: Henri? I hope you are in here and can hear me: it caused me great pain to say goodbye to George Washington. I do not want you to feel that kind of pain! I want to take you to France! You can live with me there and help me tell the world of this amazing new thing called Liberty!
Hearing no response, a deeply saddened Lafayette begins to leave when Henri emerges from his barrel. Lafayette runs back to lift him out and they hug, with Henri chirping "Thank you for chasing me!"
Also in "Going Home", near the very end of the episode, Sarah's mother, Lady Phillips, comes to America from England to be with her daughter again and, hopefully, her husband.