Why did the writers of the constitution feel the need to establish a national court system

Everyone was kind of doing their own thing at the time- making decisions they'd regret and abiding by what they thought was right. Eventually, the men who wrote the constitution, including James Maddison and Thomas Jefferson, thought it was a time for change and more of a constructed nation which helped them to come along the idea of writing the constitution. They figured if the rules were put into place and were to be followed, then the civilization of America would be more of a healthier environment to live in, verbally and physically.

Isay b but i'm not sure.