Overthrowing a government takes an enormous amount of planning, strategy, and resources. You need political allies, troops, a new staff to fill all the bureaucratic roles and keep the system running smoothly after the takeover -- it's a matter of years, if not decades, of work. Of course, you could also waltz right into the capitol building, unzip your pants, and say: "Yep, this whole state is aaaalmost big enough to hold my balls." You know, like these folks did ...
A Delusional Vice President Tries to Conquer Half of North America and Create His Very Own Empire
Vice President Aaron Burr, that guy who killed Alexander Hamilton in a duel, is best remembered as "that guy who killed Alexander Hamilton in a duel." His political career unsurprisingly collapsed after that one itty-bitty little homicide, but Burr wasn't ready to update his LinkedIn profile just yet, so he decided to create his own country to govern. This, obviously, implied huge steaming mounds of treason.
Library of Congress
Never trust a man who wears those creepy little Dracula glasses.
Burr traveled to Philadelphia and offered his services to Anthony Merry, British minister to the United States. He wanted to help Great Britain establish an independent "Empire of the West." How? By taking over the Louisiana territory, which, at the time, amounted to more than half of the U.S. -- and, hell, why not Mexico to boot? Mexico was then a Spanish territory and included what is now Texas, California, and the rest of the Southwestern United States. Hey, if you're gonna piss off an entire country, might as well go double or nothing, right? Merry was down to internationally clown, but British Prime Minister Charles James Fox thought the plan might be "super crazy. Like, even for a guy that shoots people for calling him 'voluptuary' -- that's crazy."
Saturday Evening Post
Pictured: Aaron Burr committing political suicide.
Not Pictured: The worst thing he did that year.
After the British bailed, Burr decided to press ahead regardless. He procured himself a riverboat and set off down the Ohio River, at which point he realized that, shit, he didn't have an army (pretty much the first item on any "build an empire" checklist). So, on his way to New Orleans, he started recruiting any and every settler he encountered to his cause.