Before Delaware declares separation from Pennsylvania on June 15 1776, Pennsylvania joins the revolutionary war first and refuses to give up Delaware sending troops to forcefully re-integrate it and convinces the Continental congress to recognise their sovereignty, a small civil war within the revolutionary war occurs and Pennsylvania is eventually victorious.

The American colonies later win Independence and begin negotiating a Union. Pennsylvanian representatives concede the largely unsettles north of their state to Massachuessets in exchange for their representative's support in retaining Delaware. Massachusetts aids New York in securing Vermont in exchange for recognition of their land claims.

Some federalists float the idea of states giving up territorial claims in exchange for the federal government taking on their depts. The state's representative are instead rallied to work out a deal where they resolve what few disputes remain (such as Virginia giving up claims north of Pennsylvannia in exchange for keeping everything else. They also resolve to refuse to recognize aspiring new states such as Kentucky and Vermont. 

Eventually a constitution is ratified with one key difference from our own time: "the territorial integrity of states and territories shall not be infringed and be protected by the federal government." All attempts to establish new states in territory officially recognized as part of an existing state are considered unconstitutional and is crushed by federal troops (very few at first), but mostly by state militias.

DC is never established as this would require Maryland giving up land to the federal government, which is unconstitutional. The US never establishes an official capitol, the President continues to conduct business from wherever they live, the supreme court takes up residence in various courthouses as they travel the country. Congress cycles their meeting places around a handful of halls, most frequently Federal Hall in New York where most federal archives and such are kept for convenience

By the wording on the constitution the Louisiana territory can not be divided and must be admitted as a single state. Though many states argue that all of its territory north of Georgia's southern border belongs to them, the supreme courts rules that the founding states' territories only expend to the Mississippi as that was the extent of the country's territory at the time of the ratification of the constitution as set out in the the Treaty of Paris.

The path of American expansion west continues as it did as in our timeline. Texas is acquired from Mexico but is reduced in size as Louisiana's territorial claims are superseded over it due to the government to decide on seniority to resolve territorial disputes as they already recognised the older state/ territories' claim when they admitted them before.

Lands that are annexed but that are not covered territories' claim are considered to be their own territories. This includes the Gadsden purchase. All of the Oregon territory remains united after the Oregon treaty, but the rest of the US-Canadian border is never straightened as this would require giving up north Louisianan land which is unconstitutional.

By the wording of the constitution Alta-California cannot be broken up and must be admitted as one state. This leads to the Alta-Californian-Mormon war as they don't want Mormons in their state. Alta-California wins the war and drives the Mormons back east in Northern Texas and western Louisiana. The Mormons eventually settle in the unclaimed territory between them and eventually establish a state there.

Western states are admitted at about the same rate as our own timeline despite not being fully settled, congress and the Presidency still desire expansion and simply don't provide native tribes with ballots in order to retain settler control of the new states, and they of course continue to commit genocide against them.

As the west is State-ified quicker, the sectional crisis is accelerated. This leads to John C Fremont winning the Presidency in 1856, narrowly winning Virginia (mostly by immigrant voters in the west of the state). This leads most of the southern states to declare secession in order to preserve slavery, including a part of the Virginian government. President Fremont is more radical than Lincoln and is an experienced military leader, he abolishes slavery and bring the northern industrial advantage to bear on the south sooner than Lincoln did. The alternate Confederacy may look impressive due to the larger Louisiana but it doesn't solidly control much of its northern territories and the railways are quickly laten by closer union forces. The Union wins the civil war slight quicker than in our timeline and President Fremont is more supportive of radical reconstruction, even if he is assassinated it is likely his VP isn't Andrew Johnson and is instead another republican who is also relatively supportive of radical reconstruction.

Still, radical reconstruction doesn't last forever, as eventually the electorate tire of the cost of occupation and division, the Republican party eventually lets the issue of civil rights slide and re-admit the southern "redeemer" Democrat controlled states, but later than in our timeline, perhaps in the mid to late 1880s.

When the US buys Alaska, they recognise the full extent of the Russian claim as official. When they negotiate the border with British-Canada they are constitutionally bound not to concede any of the claim so the border settles at the furthest extent in favour of Alaska as Britain concedes, not wanting to fight the US.

  
This is a very ridiculous timeline, its unlikely the US would've developed anywhere near the same way if the constitution was changed in this way but i wanted to explore wacky US state borders with the US being about the same size and how this could occur. Electoral history would certainly be altered in wacky ways.

States Indivisible