One of the truths presented by this short story is that change can be either good or bad, depending on one's outlook.
When Rip falls asleep, the colonies are still under British rule. When he awakens, the American Revolution has taken place and the government is "of the people, by the people, and for the people." Rip realizes this when he overhears people discussing politics in a lively fashion, whereas before he had fallen asleep, the people were lethargic when it came to politics because they knew they could not change anything much under the king. So this is a good change.
However, "the more things change, the more they stay the same," as the French proverb goes. Rip was a lazy, lay-about before he fell asleep, hanging around the tavern all day long, and he soon reverts to this life after he wakes up. The picture that used to hang over the door of King George is now labeled "President George Washington" but Rip finds his usual spot in the tavern and takes up residence there, just as before.
Also, before he fell asleep, he had a shrew of a wife, but when he awakens, he finds she has died. This is both good and bad - he no longer has to listen to her griping at him, but his house is no longer kept clean either - another expression of the idea that change can be either good or bad.
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