The United States of America is not united, and one reason for the disunity is the existence of our 50 states.
The 50 states result in a huge, expensive, bewildering and conflicting set of laws to follow—or to disobey and risk punishment.
Many of the original state borders were caused by geography—rivers, streams, lakes and mountains that provided a bit of isolation in the colonial era. There were a few lines that were approximately straight. Many borders have been modified over the years because of the discovery of ancient records, improved surveying technology, and even movment of land and water. At least one northern American town can be reached only by passing through Canada.
Some later states also had geographical borders, but most of the recent borders were straight lines, and were absolutely arbitrary.
Most American state borders do not enclose affinity groups, or isolate those groups from very different people across an imaginary line. The citizens of CT are not much different from those in neighboring NY, MA or RI.
The different sets of laws are a stupid burden. Why should my rights, obligations and expenses change if I move an inch over the border from Greenwich, CT to Port Chester, NY? Why are their diffewrent exams for certifying profesionals in different states?
States are remnants of ancient times. They are mostly a hindrance. They benefit only bureaucrats. We could manage fine with national and local governments, and regional planning groups.
When we ditch the states, we can also ditch the absurd Electoral College. We'll also get rid of "states rights"—a phrase that is a euphemism for "I hate black people."
How the States Got Their Shapes is an excellent book and TV series.