If you're reasonably up on your American history, you might know that Washington wasn't always the capital. Philadelphia served as the original capital while Washington was being built.
Fun fact, Congress met in other places besides Philly while they got their feet under themselves, and any place they met starting with the First Continental Congress in 1774 is counted as a capital. This means that, in addition to Philadelphia and Washington, the United States also saw its capital as:
*Baltimore, MD (2nd Continental Congress)
*Lancaster, PA (2nd Continental Congress)
*York, PA (2nd Continental Congress)
*Princeton, NJ (Articles of Confederation)
*Annapolis, MD (Articles of Confederation)
*Trenton, NJ (Articles of Confederation)
*New York, NY (Articles of Confederation, Constitution)
We have states, too. A lot of them have gone through their own bit of capital-shuffling. Even counting only the time a state served as its own entity as opposed to someone else's (Wisconsin, for example, would be counted from 1836, when it became the Territory of Wisconsin, and not from 1788, when it was part of the Territory Northwest of the River Ohio), most states have had at least one capital change, and sometimes a whole mess of them.
Every one of them had to happen for a reason. You don't just do something like swap capitals on a whim. So, let's talk about four of those past capitals.
*Bannack and Virginia City, Montana
Bannack is a ghost town now. Why are they a ghost town?
Well, why were they chosen as a capital, first off? Simple: gold. Why are they a ghost town? The gold ran out. The town ended up more of an Old West battlefield than anything else, and that's Bannack's real history.
Why was Virginia city the new capital? Gold. Loads of gold. Why aren't they the capital anymore? They ran out of gold.
Why is Helena the capital now? Give you one guess.
When Oklahoma was a territory, Guthrie looked pretty good. It looked like a modern town on the rise, helped along by Hobart Johnstone Whitley, aka the 'Father of Hollywood'; he came up with the name 'Hollywood', and his stamp of civic development can be seen all over Los Angeles. It's estimated that he founded some 140 cities, and in every one, he made sure to build a hotel and a bank. All in all, a very good name to have on your side. Guthrie certainly thought so, asking him to be the first governor of the state. Whitley in turn petitioned Congress to make Guthrie the capital, as it was ultimately their call. Congress went along with it.
Then Oklahoma gained statehood.
Suddenly it wasn't Congress' call anymore. It was the state's. And the state, according to the book 'Oklahoma: A History of Five Centuries', preferred Oklahoma City, voting it the capital over Guthrie and Shawnee in a blowout. Oklahoma City would get 70.8% of the vote, Guthrie only 23%, with Shawnee getting the other 6.2%. Not only was Guthrie out, but the state seal was moved out of Guthrie in the dead of night, ala the Baltimore Colts being moved to Indianapolis.
Guthrie went to the US Supreme Court to try to get the capital back, on the basis that the move was made immediately in 1910 as opposed to the date the move was supposed to happen as per the state constitution- 1913- but in the 1911 case Coyle v. Smith, the Court ruled 7-2 that a state could in fact determine its own capital and that the state constitutionally-mandated delay was itself unconstitutional.
Guthrie never got over the loss. To this day they still identify chiefly with the fact that they were once the capital of Oklahoma.
There was a gigantic fight, when Wisconsin gained territory status, about who would get to be the capital. It couldn't be the one they were using as part of the Territory of Michigan, because that was Detroit. It shouldn't come as much of a surprise to learn that everybody wanted the capital to be in or near them. Cassville was proposed, Prairie du Chien, Racine, Fond du Lac.
Then Andrew Jackson appointed Henry Dodge to be the territorial governor. Dodge had absolute veto power, and would have a huge edge in picking the capital.
And Henry Dodge selected Belmont, a tiny place in southwest Wisconsin that actually wasn't even really a town so much as a speculation, ostensibly on the basis that it was at the time in the middle of the territory. Even the Wisconsin Blue Book calls out Dodge's stupidity here, wondering why he didn't just pick the nearby and already-established Mineral Point.
Dodge caught a ton of flak for the choice, and backpedaled within a month, saying he'd go along with anywhere the legislature could agree on. But for now, it was Belmont. The legislators would hammer out a state constitution there.
'There' turned out to be a couple of buildings in the absolute middle of nowhere, with the legislators crammed into two buildings which would be fine housing single families, but were completely unsuitable for dozens of people at once. And also there wasn't any heat or water. And it was winter. In Wisconsin. In 1836. And the food sucked. According to the Dubuque Visitor, "Empty stomachs make clear heads, but not good laws. The Lord deliver us from a set of hungry legislators."
Enter James Duane Doty, a land speculator that had surveyed Madison, traveled to Belmont promoting it, and by the end of the session had sold deeds to 16 legislators, two clerks and Dodge's son. It was open lobbying, everyone that caught wind of it was disgusted by it, but then, every other city in the running had a Doty of their own. Doty's just the guy who won the day. Madison then had to fend off votes replacing it with just about every city on the map- Milwaukee, Racine, Belmont, Cassville, Mineral Point, Portage, Platteville, Koshkonong, Peru, and on and on and on.
Madison, however, had to be built itself, and Burlington in what is now Iowa would serve as a placeholder until... well, until Iowa became a state and snapped up Burlington, forcing an early move to Madison.
What of Belmont? It couldn't even get the attention of the railroad afterwards; when the tracks were laid three miles to the southeast, the entire town simply packed up and moved to where the track was. You have the two buildings still standing, but otherwise it's farmland on a back road.