Collected official U.S. state boundaries

[Kimmy_Gibbler]

My question is basically as you might surmise from the title: Is there an online source that identifies the official boundaries for each state in the union, in a metes and bounds sort of way?

Wikipedia has them for a few states, but not all. For instance, for Illinois (one of the states that it does provide this information for) it gives:

Illinois’ eastern border with Indiana consists of a north-south line at 87° 31′ 30″ west longitude, from Lake Michigan to the Wabash River, above Post Vincennes. The Wabash River continues as the eastern/southeastern border with Indiana, until the Wabash enters the Ohio River. This marks the beginning of Illinois’ southern border with Kentucky, which runs along the northern shoreline of the Ohio River. Its western border with Missouri and Iowa is the Mississippi River. Its northern border with Wisconsin is fixed at 42° 30’ north latitude. The northeastern border of Illinois actually lies within Lake Michigan, within which Illinois shares a water boundary with the state of Michigan.

But for other states, it does not. For Pennsylvania:

The bounds of the state are the Mason-Dixon Line (39° 43’ N) to the south, the Delaware River to the east, 80° 31’ W to the west, and the 42° N to the north, with the exception of a short segment on the western end, where a triangle extends north to Lake Erie.

In the first place, it does not tell you the meridian of longitude at which its northern boundary turns north to Lake Erie. Secondly, it’s inaccurate and does not account for the Twelve-Mile Circle between Pennsylvania and Delaware.

So, a comprehensive and accurate resource is to be desired.

[Bytegeist]

Perhaps this page and this page will be helpful?

From that second page, the download file “statesp020.tar.gz” unpacks into a “shapefile” — really a bundle of related files, the formats of which are documented here. The shapefile contains boundary data in the form of polylines, chains of latitude & longitude coordinates.

That of course gives you the boundaries in raw coordinates, not English descriptions like “the south bank of the Potomac River”, which might be what you’re really after.

[Elendil_s_Heir]

I’ve heard good things about this book: Amazon.com

[Bearflag70]

You might check the state constitution for a state boundary.

California Constitution of 1849

Article XII.

Boundary.

The Boundary of the State of California shall be as follows :

Commencing at this point of intersection of 42d degree of north latitude with the 120th degree of longitude west from Greenwich, and running south on the line of said 120th degree of west longitude until it intersects the 39th degree of north latitude; thence running in a straight line in a south easterly direction to the River Colorado, at a point where it intersects the 35th degree of north latitude; thence down the middle of the channel of said river, to the boundary line between the United States and Mexico, as established by the Treaty of May 30th, 1848; thence running west and along said boundary line to the Pacific Ocean, and extending therein three English miles; thence running in a northwesterly direction, and following the direction of the Pacific Coast to the 42d degree of north latitude, thence on the line of said 42d degree of north latitude to the place of beginning. Also all the islands, harbors, and bays, along adjacent to the Pacific Coast.

Current California Constitution revised in 1879:

CALIFORNIA CONSTITUTION
ARTICLE 3 STATE OF CALIFORNIA
SEC. 2. The boundaries of the State are those stated in the
Constitution of 1849 as modified pursuant to statute. Sacramento is
the capital of California.

California Government Code sections 110-127

[Kimmy_Gibbler]

@Elendil_s_Heir

I’ve heard good things about this book: Amazon.com

Ah, the very book I had in mind. I was wondering whether anyone—independently of the book, of course—put up similar information online. I don’t believe that official boundaries can be copyright. And one wonders whether the author included a copyright trap at all.

@Bearflag70

You might check the state constitution for a state boundary.

My main worry is that each state will include this information in different places. A Constitution here, a Territorial Act there, the Second Organic Act somewhere else. Thus I was curious if somebody already went to the effort of collecting it all in one place and online.

If only geocities were still around, this could have been my labor of love.

[Bytegeist]

@Elendil_s_Heir

I’ve heard good things about this book: Amazon.com

@Kimmy_Gibbler

Ah, the very book I had in mind.

Damnit, I knew of that book and should have mentioned it.

One thing that’s interesting (to me anyway) is how long some state boundary disputes have lasted. For example, Pennsylvania and Delaware quarreled over this tiny sliver of land until 1921. Connecticut has been recently re-surveying its border with Rhode Island. (You’d think that one should be long settled.) And Michigan disagrees with Wisconsin ever so slightly over how a segment of their northern land border is defined, though neither state has fussed about it apparently.