A treasury note is like a special piece of paper that the government printed a long time ago. Think of it like a ticket that you can keep and use later to buy something. But instead of buying a toy or candy, these pieces of paper could be used to pay for things that the government needed, like building roads or paying soldiers.
The treasury notes were made by the government in the 19th century, which was a long time ago when people wore different clothes and didn't have smartphones or computers. Back then, the government needed a way to pay for all the things they wanted to do, like building new buildings or roads. So they printed these pieces of paper and said they were worth a certain amount of money.
People who had the paper could keep it until they needed to use it to pay for something. They could also give it to someone else and that person could use it too, just like when you share your toys with your friends.
Sometimes, the government would make more of these treasury notes because they needed more money to do more things. But people started to worry that the government was making too many of these pieces of paper, and they wouldn't be worth as much anymore. This is called inflation, and it's like when you have too many toys at home and they all become less special.
Even though treasury notes are not used much anymore, they were very important for the government a long time ago because they helped to pay for important things that helped the country grow.