Have any two or more US states ever had conflicts with each other?

Besides the US Civil War?

I will let others bring in more details but it does happen. Border disputes have happened as well as arguments over other assets. The structure of the U.S. tends to thwart any big disputes however. States have their own militaries, the National Guard units, but they can’t be used to fight another state. Probably the biggest reason states can’t get into huge fights is that the Constitution specifically spells out an Interstate Commerce Clause that prohibits states from interring in commerce across state lines in most ways so that tends to kill disputes before they start.

Ohio and Michigan almost went to war. Both laid claim to Toledo.

When it was resolved, Ohio got Toledo and Michigan got the UP. If you’ve ever been to Toledo, you will quickly realize that Michigan got the better end of the deal.

In legal disputes between states, the Supreme Court has original jurisdiction. That is, they hear and decide the case first; there are no prior lower level courts.

A recent example is Virginia vs. Maryland, decided December 9, 2003. It involved control of the Potomac River.


How bout a dispute between two American Colonies ? (Actually, British Colonies in America).

One of the big things on the “to do” list at the constitutional convention was resolve the various claims to lands in the west, as the original grants of many of the states (when still colonies) nominally included all of the lands to their west until the Pacific was reached. There was substantial overlap between territories claimed by many of the states. Vermont (or the “Hampshire Grants”) was contested between NY and NH even before the revolution.

THe Supreme Court has tried to avoid participating in some current quarrels. New Jersey is unhappy with the fact that due to the reading of the 1682 treaty establishing the borders of Delaware, the latter state has jurisdiction over the lower delaware river up to the low tide mark on the New Jersey side, meaning Delaware has a great deal of control over how NJ can use their riverfront. Most river boundaries are down the middle of the river.

Until recently New York and New Jersey argued over who owned Liberty and Ellis islands.

Some quick googling came up with the following (PDF) April 12, 2007 “Report of the Special Master” in the United States Supreme Court case “New Jersey v Delaware” on the historical and ongoing nature of the dispute. (and which lists many cases of “this state vs that state” - many of which are “New Jersey vs Delaware” in its table of authorities). I am not a lawyer nor sufficiently interested to slog through it but the report shows that frictions continue.


If you are going to consider the colonies pre-revolution, there were a several border and land claim disputes, which escalated to various levels. New Hampshire and New York both claimed Vermont, for instance. What amounted to a smoldering brush war was going on over it before the revolution, and Vermont become “The Republic of Vermont” for 14 years before being admitted to the union.

Maryland and Virginia have been in conflict over portions of their boundary for about 400 years now, initially due to the value of the oyster beds of the Potomac. Low level violence has not been unknown in the past.


New York State and Vermont are constantly fighting over who produces the best maple syrup.

And Texas is always taunting everyone one with “everything is bigger in Texas” remarks. Alaska told them to shut the hell up or it would split itself in half and Texas would be the third biggest state.

It gets ugly out there.

I’ve read that water rights are becoming an interstate issue and will be more of one in the future, particularly in the West. I think I read in the newspaper that we’re working out agreements with Georgia in that area now.

Additionally, there are arguments between states over things like road easements in wilderness areas, a recent issue here.

Not just in the future - Arizona v. California was a pretty big battle over water, and is to some extent continuing.

Figuring out the apportionment of the Colorado River was also a problem for all the states along it (again something that will only get much worse in the future).

Forgot to mention the most important detail - the governor of Arizona actually sent the AZ National Guard to prevent construction of the Parker Dam (which was eventually completed). No shots were fired, but it could have turned even uglier.

Crafter_Man, I always explain it as Ohio and Michigan fought over who got Toledo. Ohio lost.

I believe Wyoming and Colorado had come pretty close over where Buffalo Bill should be buried.

Pennsylvania and Maryland disputed the border between the two, hence the Mason-Dixon Line.

Some say the Civil War really started with the Kansas-Nebraska-Missouri border raids between pro- and anti-slavery factions in the Kansas-Nebraska territory and neighboring states.

New York has fought with other states over pollution/acid rain.

There’s an ongoing dispute between NH and ME about who owns the Portsmouth Naval Shipyard.