The Unification Act is like when two friends decide to become one big friend instead of two separate ones. It happened a long time ago when the United States was made up of 13 different colonies that all acted like their own little friends. They had their own rules and leaders and sometimes they even fought with each other!
But then they realized that it would be better if they all worked together as one big team. So they made the Unification Act, which was a special set of rules that all the colonies agreed to follow.
This act made the United States into one big country with one big leader, called the President. It also gave everyone the same rights and freedoms no matter where they lived. So now instead of fighting with each other, they all work together to make America a better place.